LANDOVER, Md. -- Washington Redskins quarterback Robert Griffin III, under siege during limited action against the Detroit Lions on Thursday, suffered a concussion in Washington's 21-17 preseason victory.

Griffin left the game in the second quarter. He suffered a stinger in his shoulder as well, but coach Jay Gruden said Griffin's shoulder is OK.

A Redskins executive told ESPN's Britt McHenry on Friday that Griffin "is fine" and the timetable for his return is "right now, next Saturday for our game, but [we] still need to make sure he is right."

The Redskins play a road game against the Ravens at 8 p.m. on Aug. 29.

Griffin reached out on Twitter on Friday.

Thankful for all the prayers and well wishes from everybody. Appreciate y'all #GodsGotIt — Robert Griffin III (@RGIII) August 21, 2015

The NFL's concussion protocol, which Griffin is in, does not specify a time frame for a player's return, but Griffin will be reassessed and must be approved to return by an independent neurologist.

After Thursday's game, Gruden said Griffin would follow the protocol for a concussion and will be re-evaluated.

"We'll have to wait and see," Gruden said. "I would imagine, depending on how long he is out, he is still going to be our starter. We have to wait and go through the whole process and see how he recovers, see how fast he recovers. I have no idea as far as third preseason game, fourth one, right now."

Griffin was hit after almost every pass play during a little more than a quarter of action Thursday, and the last hit ended his night. Griffin started to run and lost the ball on his own, and when he fell to recover it, Lions defensive lineman Corey Wootton fell on top of him. Griffin's right arm was extended, and Wootton fell on Griffin's head.

Griffin lay on the ground for several minutes before walking off under his own power and headed to the locker room with a glum look on his face. He gave a thumbs-up to the crowd.

Stuff Your Sorries In A Sack Robert Griffin III was sacked three times in four drives Thursday night; however, that's not exactly a new development. Griffin had the league's highest sack rate (sacks per dropback) last season. Sack pct. Robert Griffin III 12.5% Blake Bortles 10.0% Josh McCown 9.5% -- ESPN Stats & Information

Griffin struggled all night, but it was largely a function of poor pass protection. It didn't help that left tackle Trent Williams was sidelined; his replacement, Willie Smith, was beaten often. The Redskins also have two inexperienced blockers on the right side in rookie guard Brandon Scherff and second-year tackle Morgan Moses. Both had their issues.

Griffin, who said earlier in the week that he feels he is the best quarterback in the NFL and he just has to prove it, had a rough night. He completed 2 of 5 passes for 8 yards and was sacked three times. But he was hit on six pass attempts, including on quick drops on which he threw quickly.

Gruden said he did not regret having Griffin go back in the game for a fourth series, even after the first three went poorly.

"We felt confident in our tackle and our offensive line to try and get something going there with the fourth drive," Gruden said. "Unfortunately, it didn't happen."

The Redskins' special teams was also dealt another blow Thursday, when linebacker Adam Hayward suffered a season-ending knee injury in the second quarter, a source confirmed. It is Hayward's second major injury in as many seasons; his 2014 campaign was cut short by a season-ending leg injury in Week 12.

The Redskins' special teams had already lost one of its leaders a week ago, when tight end Niles Paul dislocated his left ankle in the team's preseason opener.