Jimmy Garoppolo was absent as the San Francisco 49ers resumed practice on Monday fuelling doubts about his availability for Sunday's game against the Houston Texans.

The 49ers quarterback has been battling a thumb injury which was aggravated in Thursday's 20-17 loss to the Tennessee Titans.

Garoppolo's status for Sunday's game is unknown but he is considered day-to-day, meaning Trey Lance could deputise for him.

"We knew his thumb was hurting him," 49ers head coach Kyle Shanahan told reporters. "We thought he jammed it sometime in the game, so he tells us right when he comes to the bench."

He added: "I think this last month of Trey has been his best consecutive four weeks at practice since we've had him.

"He's had a number of good days and he's had some bad days like most guys do, but as far as his consistency and stuff, I feel this last month has been his best."

Shanahan indicated Garoppolo suffered the injury in the second quarter against the Titans when sacked by Denico Autry, with the QB playing on but struggling with two costly interceptions.

The 49ers will re-assess Garoppolo's availability for Sunday's game on Wednesday.

Garoppolo has a completion rate of 68 percent this season for 3,494 yards with 19 touchdowns and 10 interceptions across 14 games.