The 49ers have lost 30-year old starting center Eric Heitmann for the next 6-8 weeks after fracturing his left fibula in practice.  This is a big blow to the Niners.  Heitmann started all 16 games for the 49ers last season and he has played in 119 games (114 starts) in his 8 years in the NFL.  Luckily the Niners have some depth on the O-Line as David Baas will battle Tony Wragge for the starting center job until Heitmann is ready to return to action.  Baas started all 16 games at guard for the Niners last season.  He has played in 76 games (38 starts) in his 5 years in the NFL.  Tony Wragge played in 15 games (0 starts) for the 49ers last season.  He has played in 52 games (15 starts) in his six years in the NFL.  My money is on Baas to be the starting center until Heitmann is ready to return to action.