Isaac Guerendo

49ers top two backs likely out for the season Kyle Shanahan said that Christian McCaffrey did injure his PCL and it is a 6-week recovery. His season now looks like it s over. 49ers RB Jordan Mason suffered an ankle injury and also is being placed on injured reserve. (ESPN - Adam Schefter) FF Today's Take: The news on McCaffrey was somewhat expected given how he fell on his final carry in Week 13. The news on Mason was a shocker since it was assumed he was pulled late due to the uncompetitive nature of the game. This leaves Isaac Guerendo as the next man up for the 49ers. While fantasy managers are certain to go head over heels for the rookie on waivers this week, it is important to note it has been a couple of months since a San Francisco running back has topped 20 PPR points. Guerendo should be considered a regular fantasy starter moving forward, but it might be a bit much to place the potential "league-winner" title on him - especially if LT Trent Williams (ankle) continues to miss time.

Christian McCaffrey and Jordan Mason both are headed to injured reserve, opening the door for rookie Isaac Guerendo to start for San Francisco.

With Christian McCaffrey (knee) and Jordan Mason (ankle) in line to be placed on injured reserve, Guerendo is expected to take over as the 49ers' starting running back, Adam Schefter of ESPN reports.

Mason and Christian McCaffrey (knee) both landed on injured reserve on Monday, paving the way for Isaac Guerendo to become a league-winner in fantasy leagues. Mason won't be eligible to return in the regular season, meaning his year ends with a rushing line of 153-789-3. He served as the 49ers' bell cow back for eight weeks while McCaffrey was out, and was one of the top running backs in fantasy during that two-month stretch. Mason will be a restricted free agent next offseason, but could end up playing for another team in 2025 if the 49ers don't match any qualifying offers that may come his way. Mason will be 26 at the start of next season and has been a lightly-used back during the first three years of his career.

49ers HC Kyle Shanahan said after Sunday night's loss to the Bills that RB Christian McCaffrey has a PCL injury that could be season-ending. McCaffrey will likely undergo additional testing on Monday to get a better look at the damage. We should get another update on his status over the next 24 hours. McCaffrey's absence would leave Jordan Mason as San Francisco's lead back once again. He out-carried RB Isaac Guerendo 13 to four in Buffalo. Mason, who's rostered in only 37% of Sleeper leagues, is the top target on waiver wires this week.