Redskins’ Robert Griffin III suffers a concussion in exhibition with Lions

With zero help from his offensive line, quarterback Robert Griffin III repeatedly wound up on the turf until leaving with a shoulder stinger and a head injury after being sacked three times and fumbling twice Thursday night in the Washington Redskins’ 21-17 exhibition victory over the Detroit Lions in Landover, Md.

Redskins Coach Jay Gruden said Griffin sustained a concussion and he had “no idea” how long Griffin would be sidelined.

Griffin completed two of five passes for eight yards on four possessions. On his final play, early in the second quarter, he started to scramble but dropped the ball despite no contact. As he went to the ground to try to corral the loose ball, Lions defensive end Corey Wootton landed on Griffin.

Matthew Stafford looked good for the Lions, going six for eight for 78 yards and leading one scoring drive that ended with Matt Prater’s 49-yard field goal.

When Griffin got hurt, he stayed down on the field for about five minutes and was tended to by trainers, while some teammates kneeled nearby. When Griffin eventually rose, he slowly stepped to the sideline, then kept going until he left the field and entered the tunnel that leads to the Redskins’ locker room. Griffin gave a thumb’s up to spectators as he trudged away.

Good night for Manziel

Johnny Manziel threw a touchdown pass and maybe closed the gap on Browns presumed starting quarterback Josh McCown in Cleveland’s 11-10 loss to the visiting Buffalo Bills.

Buffalo’s EJ Manuel, attempting to beat out Matt Cassel and Tyrod Taylor for the starting job, threw a 14-yard touchdown pass to Andre Davis with 1:31 left. He then connected with rookie Bronson Hill for the two-point conversion.

Manziel connected with rookie Shane Wynn on a 21-yard TD pass in the fourth quarter. Playing against Buffalo’s backups, Manziel finished 10 for 18 for 118 yards.

Cardinals lose Peters for season

Two of the Arizona Cardinals’ most significant off-season acquisitions are injured and one of them — starting nose tackle Corey Peters — is lost for the season.

Peters tore his left Achilles’ tendon in practice Wednesday. Starting left guard Mike Iupati will undergo surgery for a torn left meniscus. Iupati was hurt Tuesday in practice.

Coach Bruce Arians said Iupati is out three to eight weeks, meaning he could miss the first five games of the season.

Peters tore an Achilles’ for the second time in three seasons. He tore his right Achilles’ tendon late in the 2013 campaign.

Peters signed a three-year, $10.5-million deal with $3.75 million guaranteed. He played all five of his pro seasons with Atlanta, starting all 15 games before he was hurt in 2013. He appeared in 14 games with the Falcons last season.

Iupati, a three-time Pro Bowl selection with San Francisco, signed a five-year, $40-million contract with $22.5 million guaranteed.

Etc.

The Denver Broncos placed Marvin Austin Jr. on injured reserve after the fifth-year nose tackle missed all of training camp with a groin injury. Austin played a career-high 15 games for Denver last season. ... New York Jets offensive lineman Oday Aboushi was suspended one game without pay by the NFL for violating the league’s substance abuse policy. ... Philadelphia Eagles outside linebacker Marcus Smith left the team’s joint practice against the Baltimore Ravens on a cart with an apparent right hamstring injury.