What were the Raiders thinking?

Week 1 of the 2018 NFL season has finally arrived! As another chase for the Lombardi Trophy kicks off, NFL.com's network of reporters collects the hottest news and notes from across the league, including:

-- Travis Kelce's secret skill.

-- Why Mike Zimmer is feeling cranky.

-- How Sam Darnold made his mom cry.

But first, Jim Trotter takes a hard look at an unusual decision in Oakland ...

ALAMEDA, Calif. -- As the Raiders prepare for their season opener Monday night against the Rams, the sizable shadow of Khalil Mack continues to linger over the iconic yet struggling franchise, which traded its All-Pro end/linebacker to the Bears six days ago following a prolonged contract standoff.

The move stunned nearly everyone in the organization, most notably the players. Privately, some contend they will never understand nor agree with the decision to deal away a former Defensive Player of the Year who is entering the prime of his career at age 27. Even Raiders general manager Reggie McKenzie acknowledged the trade will "sting" for some time, adding additional intrigue to Monday night because no one knows what the psychological impact will be on the players.

You have to search long to find a situation that even remotely rivals this. One of the few occurred in 2003, when the Patriots released Pro Bowl safety Lawyer Milloy the week of the season opener against the Bills, and Milloy went on to join Buffalo and play against New England.

"Guys were pissed!" says Damien Woody, an offensive lineman on that Patriots squad. "Lawyer was a captain and one of the most respected members on the team. We proceeded to get beat down, 31-0."

I ask Woody if there might be a hangover among Raiders players.

"It's hard to say, given that I'm not in their locker room," he answers. "But what I will say is, what player likes having your BEST player traded away right before the regular season starts? If they get off to a bad start ... watch out!"

The statement is less an indictment of the Raiders' competitive character and more a reflection of the team's precarious position. It would be insulting to question how hard they will play in the opener, but a slow start ... at home ... in prime time ... on national television ... in coach Jon Gruden's return to the team after a 17-year absence ... nine days after the club's best player was traded -- watch out, indeed.

Did this move have to happen? Depends on whom you speak with in the organization. On Saturday night in a conference call with local media, McKenzie said the $125 million contract that Raiders quarterback Derek Carr signed last year had nothing to do with an inability to extend Mack; the next day, Gruden said it was a factor. On Saturday night, McKenzie said the $135 million deal that Rams defensive tackle Aaron Donald signed had nothing to do with Mack, who immediately signed a $141 million deal after joining the Bears; the next day, Gruden said that it did.

Since then, I've heard some Raiders apologists contend that the team had no choice but to move Mack, because you can't have two players on the same team making in excess of $20 million a year. Their point is that the players' salaries and bonuses would occupy too much of the salary cap, thus preventing the team from supplementing those players with other talent.

In a word, that's hogwash. If you're looking for the proper acronym, it's CYA. It's a team essentially saying, "We're doing it this way because that's the way it's always been done," which theoretically provides cover from criticism. I find it to be groupthink at its worst.

Has there ever been a situation with two players on the same team making at least $20 million each in the same season? Our research staff says no, but take a step back and see the forest instead of the trees. The more applicable question is whether signing Carr and Mack to their current deals would have eaten up a disproportionate PERCENTAGE of the salary cap, and the answer is, not really.

According to our research staff, the contracts of Carr and Mack would have accounted for 27.4 percent of this season's $177.2 million salary cap, which is less than the 27.6 percent that quarterback Matthew Stafford and wide receiver Calvin Johnson accounted for in 2011 with the Lions. And it's only slightly more than the 26.7 percent that quarterback Ryan Tannehill and defensive tackle Ndamukong Suh accounted for in 2015 with the Dolphins.

I'd be more receptive to an argument that the Raiders moved Mack because they lacked the cash flow to place into escrow the guaranteed money on another record deal, which Mack's is and Carr's was before being quickly surpassed. That makes sense.

But to say that signing Mack would have prevented them from restocking a roster that Gruden repeatedly criticizes as lacking in talent? Hogwash. Just ask yourself this: If the script were flipped and Mack had been signed to a record deal last year, leaving Carr to now seek a top-end deal, do you think the Raiders would have traded Carr?

Of course not.

NOTES FROM AROUND THE REST OF THE LEAGUE

ARIZONA CARDINALS: The ultimate chess piece. In 2016, Cardinals running back David Johnson posted 2,118 scrimmage yards and 20 scrimmage touchdowns (both NFL highs), making him the first player since LaDainian Tomlinson in 2006 to have more than 2,000 scrimmage yards and at least 20 scrimmage touchdowns in a season. Now, as Johnson prepares to come back from a wrist injury that derailed his 2017 season, we should consider Johnson solely as a playmaker and not just as a running back. At least, that appears to be the plan for Arizona's most dynamic chess piece.

"I think there's so many different ways you can use David," first-year head coach Steve Wilks told me last week after practice. "I think it's all based off each week and who you're playing and trying to create that matchup. We all know the National Football League has talent across the board, but it's about trying to find that matchup, and that's what we need to do each and every week."

Wilks feels new Cardinals offensive coordinator Mike McCoy has already done an amazing job figuring out the different ways to use Johnson, which, again, will change from week to week. Johnson has also approached McCoy multiple times throughout camp to talk about his abilities as a receiver (879 receiving yards in '16) and what he's capable of doing in a variety of roles for the Cardinals' offense.

-- James Palmer

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KANSAS CITY CHIEFS: Kelce can catch 'em -- and toss 'em! All-Pro tight end Travis Kelce threw one pass last season, against the Giants, but it was intercepted as he tried to squeeze it between two defenders. Oh, it also went 50 yards in the air.

Kelce was a high school quarterback and occasionally lined up behind center in college at Cincinnati. That experience might be making him more helpful to first-year starter Patrick Mahomes.

"It helps to have tight ends like Kelce," Mahomes said recently. "He's someone who's played the quarterback position before. He understands what you want. I think I said it before as we've gone through training camp, that he's always just in the right space and the right spot. For me, I can throw it and trust that he'll be in that spot, and that's a big thing to have for a quarterback."

Kelce believes that, in addition to benefitting Mahomes, his background gives him an advantage. Kelce led all tight ends in catches last season, with 83.

"I think it's huge," Kelce said. "Being able to be on the same page every time, I think that's kind of a broad term, but understanding where certain quarterbacks like to throw the ball in certain coverages. That's a huge advantage that I can have over people."

-- James Palmer

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MINNESOTA VIKINGS: Zimmer the Grouch. With a new quarterback and a championship-caliber team just days away from opening the 2018 season against the 49ers, is Vikings coach Mike Zimmer getting excited?

"No, I get grouchy. The grouchy coach comes out in me as opposed to the offseason coach," Zimmer told me, sitting in his office after practice Wednesday. "Now jobs are on the line. Now it's time to go prove all the work that you did, prove if you're a good coach or not. I become much more demanding this time of year."

Players say Zimmer is telling the truth, and it's nothing new, heading into the fifth year of his tenure in Minnesota.

"I think he's always grouchy, especially once training camp hits," receiver Adam Thielen told me. "But obviously, he loves to win and he wants to win so badly that he's not going to let us get away with little things that we're doing wrong."

Said tight end Kyle Rudolph: "I remember back to his first game as a head coach ... in 2014. I remember (then-receiver) Greg Jennings and myself joking around with him that week, because he was Zim all the way up until that week, and then he got grouchy. Like, 'Coach, it's just another game.' But it was his first game as a head coach, and that's kind of continued throughout his career.

"But I feel like it's that way for everyone. You've been preparing since the middle of April, and you always talk about September 9th, and it seems so far away. Now, September 9th is here and it's time to go. That's what all the preparation that we've done over the last four months is for. So, I feel like the anxiety is built just because so much work has been put into this, and you want to get started on the right foot."

-- Tom Pelissero

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NEW YORK GIANTS: An older, wiser OBJ? Following last season's Week 5 ankle injury, which required surgery and considerable rehabilitation, and after receiving a long-term $95 million extension from the Giants last month, this has been a more reflective Odell Beckham Jr.

Beckham, 25, stood at his locker Wednesday and -- with outspoken cornerback Jalen Ramsey and the Jaguars on tap Sunday -- reflected on his December 2015 meltdown against the Panthers and cornerback Josh Norman.

"I think I learned my lesson," Beckham said. " ... It's not gonna be something that you repeat." Smiling, he added that he "took the cheese" against Norman and had no one to blame but himself.

Since January, Beckham has developed a strong relationship with new Giants coach Pat Shurmur, which is not insignificant.

"There's a brotherhood in this locker room that stems from the head coach doing what he's doing," Beckham said.

Coincidentally, Tom Coughlin, Beckham's first NFL head coach and now Jacksonville's executive vice president of football operations, will be watching his Jags from the press box Sunday as Beckham returns to the playing field.

-- Kimberly Jones

How valuable is Beckham to the Giants? In Beckham's four seasons thus far, the Giants average 5.8 points per game more when he plays (22.7) than when he doesn't (16.9). With Beckham, Eli Manning has averaged 49.5 more passing yards (271.9 to 222.4), and the Giants' third-down percentage is five points higher (38.7 to 33.3).

No wonder a Giants source told me before the draft, "We have to get [Beckham] some help." The Giants, of course, drafted running back Saquon Barkley with the No. 2 overall pick. During the preseason, wide receiver Sterling Shepard thrived beyond the slot. And tight end Evan Engram isn't a rookie anymore.

Still, I asked offensive coordinator Mike Shula what makes Beckham so valuable.

"He's really talented, as we know," Shula said. "He knows and gets football, all the little adjustments that maybe sometimes you have to tell other guys, he kind of gets them. He's got really, really good hands and he's a guy that has made big plays in big situations."

Shula went on to say, "He's a big piece to our puzzle, but he's not the only piece." Not anymore.

-- Kimberly Jones

Will Beckham, Barkley be fielding booted balls? Shurmur has not closed the door on using Beckham on punt returns and Barkley on kickoff returns, and they take regular reps in those roles. Both players said they would embrace the opportunity.

So would special teams coach Thomas McGaughey, who said his response would be "a huge smile" if the duo were green-lighted for returns.

"You just never know," McGaughey said. "These guys are playmakers. Anytime you get a chance to put playmakers out on the field, that's a chance to win. That's what you want to do, trying to win the game. That's the purpose."

-- Kimberly Jones

McGaughey vowing to fight cancer. In his media session Thursday, McGaughey revealed that he has been battling cancer and receiving chemotherapy for the past two months. Doctors made the diagnosis after finding a growth in his bowel duct, he said.

"I'm not going to let chemotherapy or cancer get ahold of what I do," said McGaughey. "I'm a father and I'm a football coach. That's what I do. It's get up, go to work and earn your paycheck. You do what you do and live life."

It sounds like McGaughey and general manager Dave Gettleman, who disclosed his own lymphoma diagnosis in June and said in July that he is in remission, have been helpful to each other.

"We share our chemotherapy stories and talk about the medication," McGaughey said. "Dave is a great man. We have to fight through it and keep moving."

-- Kimberly Jones

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NEW YORK JETS: New day dawning with Darnold. There's a feeling in Florham Park that this season is all about the development of rookie quarterback Sam Darnold. Maybe not solely, but mostly. The Jets have waited so long for a franchise quarterback. On Monday, the 21-year-old Darnold will become the youngest QB to start a season opener since the 1970 merger.

With the Jets coming off back-to-back 5-11 seasons, there is no indication from Jets chairman and CEO Christopher Johnson that coach Todd Bowles and general manager Mike Maccagnan are on any kind of hot seat. To the contrary, the mood in and around the Jets has been nearly giddy, based largely on Darnold's poise this preseason, when he proved to be a quick study.

The Jets and Darnold will be tested early, with three games in 11 days, beginning Monday against the Lions and continuing with contests against the Dolphins and Browns.

But for the first time in a while, the Jets' long-term fortunes appear to be looking up. "I like what we have," Bowles said, "and I like where we are going."

-- Kimberly Jones

Darnold shares a touching milestone. Veteran receiver Jermaine Kearse, who came into the league with Russell Wilson in Seattle, says the only way he knows Darnold is a rookie is off the field. Tuesday provided one of those moments, when Darnold spoke to the media for the first time after Bowles officially named him the starter.

Darnold said his first call was to phone home.

"Mom was crying ... as usual," he said. "My dad was just pumped for me. He just said, 'This is what you worked so hard for.' So, it was a cool little moment there with them and my sister. It was fun."

Safety Jamal Adams, the Jets' first-round pick in 2017, said he told Darnold simply to "be yourself." Darnold has shown poise throughout preseason, including in interactions with the media which, in the New York market, means something.

"We celebrate all wins," Darnold said. "At the same time, I know that just because I got named the starter doesn't mean we won the game Monday night. It's awesome and I'm really happy to be a starting quarterback, but I also know I have to go out there and do my job."

-- Kimberly Jones