Jimmy Garoppolo (thumb) questionable vs. Rams; Shanahan declines to reveal 49ers' starting QB

San Francisco 49ers coach Kyle Shanahan said Friday that quarterback Jimmy Garoppolo is suspicious of playing with a thumb injury on his throwing hand, leading to a club trying to grab the last available playoff spot. A cloud of uncertainty is looming. NFC. The 49ers (9-7) visit the Los Angeles Rams on Sunday and can claim a wild-card berth with a win or tie or with the New Orleans Saints losing to the Atlanta Falcons.

Shanahan declined to name a starter, but said that both Garoppolo and rookie Trey Lance looked good in practice.

"I know what we're doing, I just don't feel like telling you," Shanahan said.

Garoppolo has been limited this week, however, after hurting his thumb in a Week 16 loss to the Tennessee Titans. Hopefully he will have surgery on it after the season. Lance made the second start of his career in place of Garoppolo on Sunday, and responded with an impressive second half to lead a 23-7 win over the Houston Texans.

Garoppolo has completed 278 of 409 passes for 3,494 yards, 19 touchdowns and 10 interceptions in a year. Shanahan has held steady since the preseason that Garoppolo is the 49ers' best choice at quarterback, despite the team investing the draft's No. 3 overall pick in Lance.

Also in play are the 49ers left to deal with suspect Trent Williams, one of the game's top offensive linemen. Williams has an elbow injury and was barred from practice throughout the week. Given the Memes' collection of talented pass rushers, Williams' potential absence could take a toll on the 49ers' offensive efficiency.