Note: Article updated to reflect new information from Tom Pelissero.

San Francisco 49ers cornerback Richard Sherman exited late in Sunday's game against the New Orleans Saints with a hamstring injury. He underwent an MRI on Monday morning and remains sore, according to Tom Pelissero of NFL Network.

Pelissero reports that Sherman suffered a Grade 2 hamstring strain, which not only puts the Week 15 matchup against the Atlanta Falcons into question, but perhaps more.

Sherman was coming off a knee sprain suffered the week before against the Baltimore Ravens and was limited last week during practices in Florida, where the team stayed between Weeks 13 and 14. Unlike the previous game, Sherman was unable to return to the field against the Saints.

"I definitely couldn't go back in this one, unfortunately," Sherman told reporters after the game. "If I could give us any kind of chance to go back in, I would have. But unfortunately, in that situation, I would have just been a liability out there with it the way it was.

"We've got a long week ahead of us to try to get it together. Like I always say, don't count me out until I'm out."

San Francisco hosts the Falcons on Sunday, December 15, and then the Los Angeles Rams on Saturday, December 21. The 49ers will close out the season with a road trip to face the Seattle Seahawks on Sunday, December 29.