ESPN

LANDOVER, Md. -- Robert Griffin III walked gingerly through the Washington Redskins locker room, his sprained right knee in a big black brace.

Teammates stood at their lockers, mixing the emotions of an improbable 31-28 overtime win over the Baltimore Ravens with the fear that their franchise player could be seriously hurt.

"We're happy that we won, obviously," left tackle Trent Williams said. "But that is concerning, knowing he went down. Everyone wants to know how he's doing."

Griffin went down during Washington's final drive of regulation Sunday, with the Redskins trailing by eight. Fellow rookie Kirk Cousins, who had played in only one other game this season, stepped in and hit Pierre Garcon for an 11-yard touchdown pass with 29 seconds remaining, then ran the quarterback draw for the 2-point conversion to tie the game.

Yet another rookie, Richard Crawford, returned a punt 64 yards in overtime to set up Kai Forbath's 34-yard game-winning field goal. The Redskins (7-6) have a four-game winning streak -- putting pressure on the New York Giants in the race for the NFC East title -- but the day's most important news was about Griffin.

After the game, Redskins team spokesman Tony Wyllie said Griffin underwent an MRI and has a sprained right knee but that "everything is clear" in terms of significant ligament damage.

Wyllie specifically ruled out a season-ending torn ACL.

Wyllie said Redskins coach Mike Shanahan will update the rookie quarterback's condition Monday. A league source told ESPN's Adam Schefter that there is "no guarantee" that Griffin will play next week against the Cleveland.

Before undergoing the MRI, Griffin said he didn't think he tore his ACL.

"I'm not a doctor, but I know what an ACL feels like," he said. "And it doesn't feel like an ACL. ... If I felt that, I'd be pretty nervous. But we won the game, everybody's praying for me, I feel pretty good right now about the whole situation. I'm not too nervous, but I'll definitely be praying during the MRI."

With the Redskins trailing 28-20 after Ray Rice's 7-yard touchdown run with 4:47 to play, Griffin started moving his team before he was tackled by Haloti Ngata at the end of a 13-yard scramble.

"I knew as soon as I got hit. I screamed. Like a man, of course," Griffin added with a laugh. "It hurt really bad."

Griffin left for one play, then returned for four more, completing two passes to get the Redskins deep into Ravens territory. But he was also hopping on one leg. Eventually, he fell to the turf and could no longer continue.

"I knew I needed to get out at that point," Griffin said. "I couldn't move. At some point you have to do what's right for the team. And if I'm playing the rest of that game, I probably would have hurt myself even more."

In came fourth-round pick Cousins, who was a clutch 2 for 2 -- back-to-back to Leonard Hankerson for 15 yards and 11 yards to Garcon.

"He's ice. Like they used to say about Larry Bird, he got ice water in his veins. That's the best thing you can say about Kirk," receiver Joshua Morgan said. "He was coming like nothing was even going on."

Then came some Bird-level audaciousness -- the quarterback draw on the 2-point try, a call that Griffin heard through his headphones while getting treatment on the sideline.

"It was awesome," Griffin said.

The Ravens got the ball to start overtime but went three-and-out. Seventh-round pick Crawford, getting a chance to handle punts for the first time after a disappointing set of games from Brandon Banks, had the big return to Baltimore's 24-yard line, putting the Redskins easily within the range of Forbath, who hasn't missed in 14 attempts in his debut NFL season.

It was all part of a day of big-time contributions from first-year Redskins: Sixth-rounder Alfred Morris ran for 122 yards on 23 carries with a touchdown.

While the Redskins have been in must-win mode since dropping to 3-6, the Ravens (9-4) would have clinched the AFC North with a win. Instead, they ended a 15-game winning streak following a loss, dropping back-to-back games for the first time since 2009. They are 2-2 in their last four -- all decided by three points.

"As a leader on this team I like to finish teams out," said Rice, who ran for 121 yards on 20 carries. "I don't want to be known as, 'Yeah, we get them close in the fourth quarter, and the Ravens are going to give it away.' That's never been us. That's not going to be us."

Joe Flacco completed 16 of 21 passes for 182 yards and three first-half touchdowns for the Ravens, and third-round pick Bernard Pierce ran for a season-high 53 yards. Anquan Boldin, who passed the 10,000-yard receiving mark, caught two touchdown passes and set up a third with a 28-yard catch-and-tiptoe-run down the sideline.

The big accomplishment for the Ravens defense was getting RG3 out of the game -- and they still couldn't win. After sweeping their three NFC East rivals in three weeks, the Redskins now have bragging rights over their neighbor to the north.

"We knew if we didn't get the win today, obviously those other three didn't mean a whole lot," Washington coach Mike Shanahan said. "I'm really proud of how the guys played."

Game notes

Ravens RG Marshal Yanda sprained his right ankle and wore a black walking boot on his foot in the locker room. LB Jameel McClain had a neck injury, but X-rays were negative. FB Vonta Leach sprained his ankle. Rice had a left hip pointer. ... The Redskins have their first four-game winning streak since 2008 and have six 30-point games, their most since 1996. ... Washington became the first team since the 1970 merger to have two rookie quarterbacks lead fourth-quarter comebacks in the same season.

Information from ESPN NFL Insider Adam Schefter and The Associated Press was used in this report.