ORCHARD PARK, N.Y. -- San Francisco 49ers running back Christian McCaffrey suffered what is believed to be a posterior cruciate ligament (PCL) injury in his right knee during Sunday night’s 35-10 loss to the Buffalo Bills, putting the remainder of his season in doubt, according to coach Kyle Shanahan.
"I think it could potentially be season-ending," Shanahan said following the game. "A PCL injury usually takes a couple of weeks, but we’re not sure yet."
McCaffrey is set to undergo further testing on Monday to determine the severity of the injury and whether he will be able to return for any of the 49ers’ final five games.
For the first quarter, McCaffrey appeared to be in prime form, showcasing the kind of performance he had been seeking since returning from an Achilles injury. However, that momentum came to an abrupt halt in the second quarter when McCaffrey took a pitch to the right. As he planted his foot to turn upfield, he opted to slide down without contact after a 5-yard loss.
McCaffrey limped directly to the blue injury tent after the play, and after a brief examination, he headed to the locker room for further evaluation. Initially, he was listed as questionable to return, but he was ultimately ruled out at halftime.
The injury seemed to have occurred about 95 seconds earlier when McCaffrey gained 18 yards up the middle before being tripped by Bills safety Taylor Rapp. McCaffrey came down hard on his right knee but briefly returned to the game before the injury forced him out for good.
"It was frustrating," Shanahan said. "He had a great week of practice, and I could feel his urgency. He came out looking really good, and it seemed like he just got his shoestring. ... It’s tough for him, and tough for our team without him."
At the time of his injury, McCaffrey had seven carries for 53 yards and two receptions for 14 yards, including season-best runs of 19 and 18 yards.
Sunday's game marked just McCaffrey’s fourth appearance since returning from bilateral Achilles tendinitis that kept him out of most of training camp and the first eight games of the season. He had been slowly regaining his form in recent weeks and felt a breakout game was close—something his teammates had noticed before his injury.
"We all saw what he was doing, and he was on fire," said quarterback Brock Purdy. "He looked great, hitting the holes hard and making explosive plays. Losing him like that takes away from what we do as an offense. It sucks."
In McCaffrey’s absence, backup Jordan Mason stepped up, rushing for 78 yards on 13 carries, while rookie Isaac Guerendo scored the Niners’ only touchdown of the game with a 15-yard run.
Despite the efforts of Mason and Guerendo, the 49ers’ season continues to take hits. Along with McCaffrey, the team has already lost key players like receiver Brandon Aiyuk and defensive tackle Javon Hargrave to season-ending injuries, and was also missing stars such as left tackle Trent Williams, defensive end Nick Bosa, and cornerback Deommodore Lenoir on Sunday night.
With a 5-7 record, the Niners are clinging to slim postseason hopes, but are realistically focused on breaking a three-game losing streak, which has included two losses by at least 25 points.
"It's not a great feeling, but it’s football," said tight end George Kittle. "People go down, and we need guys to step up. Whether it’s starters or new guys getting into the rotation, we all belong in the NFL and have play-making abilities. It’s on all of us to keep pushing forward."