49ers player Christian McCaffrey (calf) surprisingly unable to play against Jets

SANTA CLARA, Calif. – After declaring Friday that he had no doubts about his ability to play, San Francisco 49ers running back Christian McCaffrey has been ruled out for Monday night’s opening game against the New York Jets.

McCaffrey has been battling a calf and Achilles injury since the early days of training camp, which coach Kyle Shanahan announced on Aug. 6. Shanahan said at the time that McCaffrey would be out for a few weeks and would not participate in preseason training, but it was expected that McCaffrey would be healthy in time for Monday’s game.

On Friday, McCaffrey even said he was confident he would get his usual heavy workload. And general manager John Lynch told radio station KNBR on Friday morning that McCaffrey was “out there and ready to play.” But even after participating in four practices this week on a limited basis, McCaffrey was removed from the game as one of their six inactive players (plus the third backup quarterback) about 90 minutes before the game. The Niners considered McCaffrey’s participation against the Jets questionable, although teammates and coaches had expressed optimism about his chances to play and contribute anywhere near his usual level.

“He looks like Christian to me,” running game coordinator Chris Foerster said Friday. “You have to practice, and the guys that haven’t practiced are, I don’t want to say rusty, but there’s always something that changes just because they haven’t practiced every day. It’s just that daily grind, day in and day out. But he’s looked good.”

McCaffrey battled a similar injury at the end of last season, suffering it in a Week 17 win over the Washington Commanders and then missing a meaningless Week 18 game against the Los Angeles Rams. He returned for the NFC Divisional Round against the Green Bay Packers about three weeks after that initial injury. Shanahan said Saturday the injury McCaffrey is battling is similar to that one.

Before returning to practice on Tuesday, McCaffrey appeared to be able to move well during practice, and when he spoke to reporters on Friday, he said he was feeling “a lot better.”

McCaffrey is the NFL’s reigning Offensive Player of the Year after recording 1,459 rushing yards, 564 receiving yards and 21 total touchdowns in 2023.

Without McCaffrey, Jordan Mason is expected to start at running back. This would be Mason’s first career start after averaging 5.6 yards per carry in 33 career games. The former undrafted free agent from Georgia Tech never had more than 69 rushing yards, 11 carries or 27 snaps in a game.

Veteran Patrick Taylor Jr. and rookie Isaac Guerendo are the team’s other active running backs on Monday night.

Elijah Mitchell, the team’s backup running back from last season, is on the injured list and will miss the rest of the year with a hamstring injury.