SANTA CLARA — The 49ers placed wide receiver Mario Manningham on season-ending injured reserve Friday as a result of a knee injury.

Coach Jim Harbaugh declined to give specifics on Manningham's situation, in particular whether the injury is related to the one that sidelined Manningham for the latter part of last season and the first half of this season.

Harbaugh deferred to Manningham and team doctors, none of whom was available to the media Friday.

Manningham caught nine passes for 85 yards in a limited role upon his return. Rookie Quinton Patton is expected to play a heightened role in Manningham's absence.

Mario Manningham will miss the remainder of the season after the 49ers placed him on injured reserve on Friday with a knee injury.
Mario Manningham will miss the remainder of the season after the 49ers placed him on injured reserve on Friday with a knee injury. (Associated Press)

Manningham is in the final season of a two-year contract he signed with the 49ers before the 2012 season. Therefore, it's conceivable that he has played his final game for the 49ers.

The 49ers did not make a corresponding move to fill the vacancy on their 53-man roster, though they still might do so before Sunday's game against the Arizona Cardinals.

Manningham signed with the 49ers last season and played a key role before he suffered a torn ACL and PCL that required surgery late in the season.

He missed all the offseason workouts and training camp while he recovered from his injury. He debuted against the Carolina Panthers on Nov. 10 and appeared in six games.

He attempted to practice Thursday but ended up on an adjacent field with a team athletic trainer.

Patton played in place of Manningham against the Atlanta Falcons on Monday night, but he didn't have any passes thrown his way on his 18 snaps. Fellow backup Kassim Osgood caught a pass for 17 yards for his first reception of the season.

For more on the 49ers, see Cam Inman's Hot Read blog at blogs.mercurynews.com/49ers. Follow Steve Corkran on Twitter at twitter.com/CorkOnTheNFL.