49ers RB Christian McCaffrey out Week 18 with mild calf strain - ESPN

SANTA CLARA, Calif. — After wrapping up the NFC's top seed and earning a first-round playoff bye Sunday, the San Francisco 49ers are still working through how they will deploy their starters in their regular-season finale. But one key player has already been ruled out.

Niners coach Kyle Shanahan said Monday that star running back Christian McCaffrey is dealing with a «mild» strain of his right calf and will not play in Week 18 against the Los Angeles Rams.

The good news for McCaffrey and the Niners is the injury isn't thought to be serious and McCaffrey will be ready in time to prepare for the team's first playoff game.

«We're real confident on that,» Shanahan said. «It was good news. It could have been a lot worse. We're happy that they'll take care of him this week and hopefully he'll start getting to go [in practice] during our off week.»

Because the Niners have already wrapped up the top seed, they essentially get an extra week to rest players who need time to get healthy. They won't play a meaningful game until the divisional round, which is slated for Jan. 20-21.

McCaffrey injured the calf early in the third quarter of Sunday's win against the Washington Commanders. He had 91 scrimmage yards before departing but said after the game he didn't believe the injury to be serious, a suspicion that was confirmed Monday.

«I think it was minor and just made the smart move, especially not knowing what was going to happen next week,» McCaffrey said. «I didn't just want to go in there and make it any worse. With certain things, you can't be dumb about it.»

With McCaffrey out, the Niners turned to Elijah Mitchell to carry the load. He finished with 80 yards on 17 carries with a touchdown. The 49ers also have Jordan Mason and