Robinson will require season-ending foot surgery, Rams head coach Sean McVay told reporters following Sunday's loss to the Kansas City Chiefs. NFL Network Insider Ian Rapoport reported Allen has a stress fracture that would require a screw upon surgery.
Robinson signed a three-year, $46.5 million deal with the reigning Super Bowl champions as a free agent in March.
However, he failed to ever find a groove and was a microcosm of the Rams' offensive struggles.
Robinson's first season with L.A. ends with 33 catches for 339 yards and three touchdowns in 10 games.