Garoppolo played the entire first quarter Saturday and made the most of the extra time, completing 10 of 12 passes for 136 yards with a touchdown against an interception on 23 snaps.
The performance drew positive reviews from members of the media, including NFL.com analyst Bucky Brooks, who gave Garoppolo an A- for the performance.
Head coach Kyle Shanahan, however, pumped the brakes on the praise during his postgame press conference, pointing out a need for consistency on reads and progressions.
"It's not always perfect," Shanahan told reporters Saturday night, via the 49ers' official website. "That's what we're trying to get him to do better and better each week. Sometimes he doesn't always go through it right and still makes some plays.
"We're hard on him about that stuff. By no means was it perfect, there was a number he could be better on. There was a couple of times he didn't do it perfect on, he made a play and kept us on the field also. You've got to take the good with the bad, and just continue to keep coaching."
Garoppolo had an opportunity Tuesday to address his head coach's concerns. The signal-caller said he wasn't surprised by Shanahan's critique and agreed with the evaluation.
"I felt similarly," Garoppolo told reporters. "There were just sloppy things at times. There were some good things that we took out of the game, but we hold ourselves to a high standard."
Despite a 106.9 passer rating and completing 83 percent of his passes against the Texans, Garoppolo told reporters there was "plenty of stuff" he considered sloppy against the Texans, including a high throw that resulted in an interception.
"We are trying to be perfect on everything and I think it's good to have that mindset," Garoppolo said.
San Francisco's first-team unit should also experience more action in the third preseason game, as Shanahan told reporters Tuesday he expects the starters to play less than the first half or into the third quarter, depending on the flow of the game.