San Francisco 49ers tight end George Kittle will return to practice on Tuesday, coach Kyle Shanahan said, but running back Christian McCaffrey and offensive tackle Trent Williams will not participate, as the Niners prepare for a pivotal game against the Seattle Seahawks on Saturday night.

McCaffrey has a stiff back, Shanahan said, adding that the 29-year-old “battled it bad” against the Tennessee Titans in Week 15 and then was sore after Sunday night’s game against the Chicago Bears.

“It might have stiffened up in the game (against the Bears),” Shanahan said.

McCaffrey, who has regularly missed the first practice session each week this season, said the injury is “nothing serious.”

Williams tweaked his hamstring on the first play against the Bears while trying to make a tackle after an interception and didn’t return. Williams, 37, told Shanahan after the game that he had never pulled a hamstring before in his 15-year career. The coach said Tuesday he wasn’t sure how long Williams would be out, adding that the veteran will “give it a shot this week.”

Kittle missed the game against the Bears with a sprained ankle he suffered in Week 16 against the Indianapolis Colts. He will be limited in Tuesday’s practice, and Shanahan cautioned that Kittle’s participation does not necessarily put him on track to play against Seattle, as San Francisco’s practices will be light.

“I wouldn’t say that (Kittle has a good chance),” the coach said. “We’re barely moving today. It’s walk-through. With the short week we got, we won’t be doing much all week.”

The winner of the matchup between the 13-3 Seahawks and the 12-4 49ers will claim the No. 1 seed in the NFC, a first-round bye and home-field advantage. The Niners could fall as far as the No. 6 seed with a loss.

Also missing Tuesday’s practice were fullback Kyle Juszczyk (hip) and defensive lineman Keion White (groin), while wide receiver Ricky Pearsall (knee, ankle), defensive lineman Yetur Gross-Matos (knee) and nickelback Upton Stout (concussion protocol) were listed as limited.

Cornerback Renardo Green was expected to practice in full after missing the past two games with a neck injury.