Dorsey injured the arm at practice on Friday, which was his 29th birthday, and he was attended to by the training staff.
The six-year veteran had 41 tackles and two sacks last season, his first with in San Francisco after five with the Chiefs. The fifth pick in the 2008 draft out of LSU signed a two-year deal with the 49ers in March 2013.
49ers DT Glenn Dorsey is out for the year with a torn bicep, per source. — Adam Schefter (@AdamSchefter) August 2, 2014
- Chris Mascaro