Fill-in center Baas working to find rhythm

SANTA CLARA, Calif. (AP) - David Baas bounced a couple of snaps during team drills and knows that's not going to cut it. Afterward, he and 49ers quarterback Alex Smith stayed on the field to do more work and find their timing.

Baas is determined to win the starting job at center for San Francisco to replace the injured Eric Heitmann - and Baas sure seems to be the front-runner after getting all the repetitions with the first team Tuesday morning.

Heitmann broke his left leg Monday and is expected to miss up to two months, a big blow for a unit that is determined to establish some continuity in 2010.

"It is hard, but I need to be just like him in the huddle. It's not a done deal," Baas said Tuesday of being the new center. "I have to be very confident. I put two balls on the ground today."

The Niners' new-look offensive line, featuring rookie first-round picks Anthony Davis and Mike Iupati, will get its first real test in an exhibition opener Sunday at Indianapolis.

Baas lined up at center just once in his first five NFL seasons, and not since Dec. 31, 2006, at Denver. That after being a regular in the spot as a senior at Michigan in 2004.

"You've got to be versatile in this league," Iupati said. "There are a lot of people here who can play a lot of positions."

Interestingly, Baas earned his first start as a rookie on Dec. 4, 2005, against Arizona to replace Heitmann at right guard. Heitmann had been moved to center to take over for the injured Jeremy Newberry. Baas started the final five games that year.

Baas' transition to leading the line and calling the signals up front has to happen in a hurry. Offensive coordinator Jimmy Raye ideally would like to have a starter in place by the third exhibition game.

"I know it has to be quite quick," Baas said. "We've got to be on the same page. If the offensive line can't work together, the offense can't work together."

Raye realizes he has a daunting task of preparing a line featuring a new center and a pair of talented, yet raw, rookies.

A year ago, Raye spent much of his first year as San Francisco's top offensive coach shuffling the offensive line. But Heitmann was a steady presence during that time. At least the current situation doesn't come in the middle of the season with "the game-week pressure," Raye said.

"Huge," Raye said of his task now. "The center in our system of football is basically the backup quarterback. You don't really think about losing your center. It's a unique deal. ... I think we made a step today, once we got over the initial shock that Eric's going to be (out) 4 to 6 weeks."

Baas will be challenged for the job by Tony Wragge and Cody Wallace, though it appears to be Baas' spot to lose. Raye said the coaches will meet on their flight Saturday to Indianapolis to determine how many snaps the starters play in the first preseason game.

Baas is only worried about doing all he can to be sharp.

"You've just got to keep going and try to improve on your techniques and your calls," said Baas, who has bounced back since sustaining a mild concussion during the first full-pads practice Aug. 2. "For me it's just coming out and getting better.'

Baas' linemates aren't concerned about him being ready come the season opener at Seattle on Sept. 12.

"Dave's always been a hard worker," said left tackle Joe Staley, who missed seven games last season with a sprained knee. "He's a perfectionist. It might not be coming right now, because it's kind of new, but he's definitely going to work until he gets consistency."

Notes: The 49ers signed LBs Bruce Davis and Brandon Long and waived/injured LB Martail Burnett (sprained knee). Both new guys practiced for the first time Tuesday. Davis is the son of Bruce Davis Sr., who played offensive tackle for the Raiders from 1979-87. ... TE Vernon Davis and WR Michael Crabtree got the morning practice off from Mike Singletary as veteran courtesy. ... Left CB Nate Clements, who missed the final nine games last season with a broken right shoulder blade, picked off a pass by Smith during 11-on-11 drills that was intended for Ted Ginn Jr.