Updated

San Francisco 49ers tight end Vernon Davis is shaping up to be a game-time decision for Sunday's matchup against the Indianapolis Colts as he battles a recent hamstring injury.

Davis strained his left hamstring during the fourth quarter of last Sunday's 29-3 loss in Seattle and has not practiced at all this week. The 49ers have officially termed him questionable to play in the Week 3 tilt.

The talented eighth-year pro ranks second among San Francisco players with nine catches and 118 receiving yards through the first two games and had two touchdown receptions in the Niners' season-opening win over Green Bay.

Rookie Vance McDonald, who has two catches totaling 44 yards over the season's initial two weeks, would draw the start if Davis cannot suit up.

Defensive lineman Ray McDonald is also questionable for Sunday's contest due to a tender ankle, though he did take part in Friday's practice after sitting out the previous two days' sessions.

Safety Eric Reid is questionable as well, with the rookie still awaiting clearance from a concussion he sustained against the Seahawks.

Head coach Jim Harbaugh said he does anticipate outside linebacker Aldon Smith playing in Sunday's game. The standout pass rusher was arrested Friday morning on charges of driving under the influence and possession of marijuana following a one-car accident in San Jose, but will apparently not face any immediate discipline from the team.

"I expect Aldon, like today, to be back to work and playing on Sunday," Harbaugh remarked.