SANTA CLARA -- Coach Kyle Shanahan already has announced quarterback Jimmy Garoppolo would be back in the 49ers' starting lineup Sunday.
The only unanswered question is who would be his backup.
Nick Mullens is back in the role as the No. 2 quarterback, as C.J. Beathard on Sunday was announced as one of the inactive players for the 49ers' game against the Los Angeles Rams.
Garoppolo struggled through the first half of the 49ers' Week 5 loss to the Miami Dolphins and was benched at the opening of the second half in the team's 43-17 loss.
Garoppolo started last week and completed just seven of 17 attempts for 77 yards and did not appear healthy on two interceptions in the final two minutes of the first half. Shanahan removed Garoppolo from the game because he did not believe he could "protect himself."
Beathard completed nine of 18 pass attempts for 94 yards with one touchdown and no interceptions in the second half. It was the second consecutive game in which Beathard entered in place of a struggling starter.
Mullens started the 49ers' games in Week 3 and 4. After throwing for 343 yards in a blowout victory over the New York Giants while Garoppolo was out with a high-ankle sprain, he struggled and was benched against the Philadelphia Eagles.
Wide receiver Dante Pettis, a disappointing second-round draft pick for the team in 2018, was inactive for a second consecutive game.
Linebacker Kwon Alexander (ankle), cornerback Dontae Johnson (groin) and running back Jeff Wilson (calf) were ruled out due to injuries.
The 49ers on Saturday made three roster moves to get additional depth on their active roster to face the Rams. The club activated wide receiver/return specialist Richie James from injured reserve. James missed the past four games with a hamstring injury.
The 49ers also elevated wide receiver Kevin White and rookie defensive lineman Darrion Daniels from the practice squad. White, the No. 7 overall pick of the 2015 pick of the Chicago Bears, also suited up for the 49ers last week. He saw most of his action on special teams.
However, the 49ers announced Daniels as one of their inactive players.