INGLEWOOD, Calif. — San Francisco 49ers tight end George Kittle will miss Sunday’s game against the Los Angeles Rams because of a hamstring injury.

The Niners removed any doubt about Kittle’s status Saturday when they officially declared him out. With Kittle unavailable, the 49ers elevated tight end Brayden Willis from the practice squad to provide additional depth behind tight ends Eric Saubert and Jake Tonges.

Defensive end Sam Okuayinonu was also elevated from the practice squad to the active roster, providing some additional depth with Nick Bosa (rib) questionable to face the Rams. Bosa was a full participant in Wednesday’s practice but limited on Thursday and Friday after injuring the rib in a one-on-one drill in Thursday’s practice.

Niners coach Kyle Shanahan said Friday that Kittle was sore after participating fully in Wednesday’s practice and reported similar soreness Thursday. Kittle then did not practice again Friday as that soreness persisted, leading him to being initially listed as doubtful.

Against the Rams, San Francisco will be without Kittle, running back Christian McCaffrey and receiver Deebo Samuel. McCaffrey is on injured reserve with Achilles tendinitis, and Samuel is expected to miss a couple of weeks because of a calf injury.

Saubert is expected to start in Kittle’s stead.

“I thought he’s done a hell of a job,” Shanahan said Friday of Saubert. “He’s stepped in well. Kittle was cramping most of the game, so he had to do a lot throughout the Minnesota game. He’s been real consistent since he’s been here. If he’s got to do it all, he’s up for the challenge. He’s shown he can help us in the passing and the run game.”