ORCHARD PARK, N.Y. – The Buffalo Bills will head into the regular season short on experience at quarterback after trimming the roster on Friday.

They did, however, ensure that one key offensive player will remain in the mix.

On the same day the new-look Bills re-signed center Eric Wood to a four-year contract extension, Buffalo placed quarterback Kevin Kolb on season-ending injured reserve and released a potential replacement, Matt Leinart.

Kolb’s future was in doubt after he suffered a concussion in Buffalo’s third preseason game. It was the third concussion of his seven-year career.

Leinart topped the list of 18 players released Friday by the Bills. The former first-round pick joined the team Sunday but struggled in his only game with the Bills on Thursday night against Detroit, completing 3 of 10 passes for 11 yards with two interceptions.

The Bills remain hopeful that first-round pick EJ Manuel will return from a left knee injury in time to start against the New England Patriots on Sept. 8. Manuel threw passes on the field prior to Thursday’s game but has yet to return to practice. If Manuel is unable to play, the Bills will start undrafted rookie Jeff Tuel.

Quarterback Thaddeus Lewis appears set to make the opening day roster. Lewis, 25, has one career NFL start and outperformed Leinart in Thursday’s loss. The Bills acquired Lewis in a trade with Detroit on Sunday.

Wide receiver Brad Smith was placed on injured reserve. The eight-year veteran suffered a rib injury against the Lions.

REDSKINS: Robert Griffin III has been cleared to play, but the saga between quarterback and coach goes on.

Coach Mike Shanahan is making Griffin — and everyone else — wait until Monday before announcing who will start in the season opener Sept. 9 against Philadelphia.

Griffin was cleared Thursday by Dr. James Andrews, who performed Griffin’s knee surgery in January. Shanahan said after Thursday night’s exhibition game against Tampa Bay that Andrews still had “concerns” about Griffin’s health that need to be addressed, but Andrews told The Washington Post that he has “no concerns.”

RAIDERS: Rookie Menelik Watson will likely start at left tackle when Oakland opens its season next week in Indianapolis despite making his debut at the position in the exhibition finale.

Coach Dennis Allen said he anticipates Watson will have the important role of blindside protector for the quarterback, but would not say yet who that quarterback will be.

Allen said he has made up his mind whether Terrelle Pryor or Matt Flynn will start against the Colts on Sept. 8 but does not want to divulge that yet for competitive reasons. He said he hasn’t even told the quarterbacks of his decision yet.

RAVENS: Coach John Harbaugh named Gino Gradkowski his starting center and also said James Ihedigbo will star at strong safety, although he emphasized that first-round pick Matt Elam will also play a significant role at the position.

Elam was viewed by many as the favorite to land the starting job at strong safety, but Ihedigbo, a former New England Patriot, worked almost exclusively with the first team during camp and started each of the three preseason games in which he played.

BENGALS: Defensive end DeQuin Evans has been suspended for the season’s first eight games after he violated the NFL policy on performance-enhancing substances for a second time.

Evans, 26, served a four-game suspension in 2011. He hasn’t played yet in the regular season for Cincinnati.

CHARGERS: Left tackle Max Starks, a 10-year veteran who won two Super Bowl rings with the Pittsburgh Steelers, was among 11 players cut San Diego.

FALCONS: Atlanta waived Brian Banks, a linebacker who was attempting to make a late start to his NFL career after spending five years in prison on a conviction that was later overturned.