The Niners also aren't sure who will be their third and fourth cornerbacks or who will return kicks for them on Sunday against the Detroit Lions, and those answers might not be forthcoming until the 1:05 p.m. kickoff at 3Com Park.
Garcia is listed as probable for the Lions, but he watched in sweats Wednesday as backup Tim Rattay took snaps with the first team. As insurance, the Niners on Wednesday re-signed veteran Rick Mirer, Garcia's backup last year who was released in September when he lost the No. 2 job to Rattay.
Garcia is expected to practice Thursday, at which point the team will have a better idea of his availability against the Lions. "Our intention right now is to play Jeff," Mariucci said Wednesday. "The only reason we wouldn't is if he couldn't get it done. But we're fairly optimistic. Tim Rattay's our backup quarterback. Rick will be our third. Everybody knows that."
The situation isn't so clear in the secondary. Third-year veteran Anthony Parker, the team's third cornerback and top backup on both sides, is listed as doubtful with a dislocated shoulder. Parker has had some complications with the shoulder since injuring it last week against the Bears, when he was playing right corner in place of starter Jason Webster, who suffered a concussion in the first half and did not return to the game. Webster is expected to return to the starting lineup Sunday. But Parker could be out weeks or even longer.
"He and his agent and the doctors are going to decide if he's going to rehab it, put it in a sling and play as soon as he can, or have surgery now or after the season," Mariucci said. "There is a concern because there's still some irritation and some pain. They have to decide where to go from here."
Veteran George McCullough and rookie Rashad Holman played in place of Webster and Parker last Sunday, when the Bears were able to execute a short-passing game to drive for two touchdowns in the final eight minutes and force overtime, where Chicago eventually won 37-31. Mariucci indicated rookie Jimmy Williams - elevated last week from the practice squad - may take Parker's place on the active roster this week, and perhaps even figure in the secondary mix.
"We're still working through how we're going to play these defensive backs," Mariucci said. Vinny Sutherland, the team's standout rookie kick returner, injured his groin late last week and was unable to play against the Bears, forcing rookie receiver Cedrick Wilson into the role. Sutherland was limited in practice Wednesday, but he said, "I'm trying to get ready for Sunday, there's no doubt about it." "It will be Vinny Sutherland or Cedrick Wilson," Mariucci said. "If Vinny Sutherland practices well, then he'll probably be that guy."