Veteran nose tackle Glenn Dorsey suffered a torn left biceps in Friday’s 49ers practice, according to multiple sources, and he will have surgery to repair the injury.
It’s unknown whether Dorsey will miss the entire season, but the injury was described as “significant.” A time line for his recovery will be decided after the surgery.
The 49ers had Saturday off from training camp.
Dorsey was injured early during Friday’s practice. The biceps injury is considered more significant than the one Ray McDonald suffered a year ago. McDonald was affected by the injury but did not miss any games because of it. All three of the team’s starters on the defensive line – Justin Smith, McDonald and Dorsey – have had either a torn biceps or triceps since Dec. 12, 2012.
Another 49ers nose tackle, Ian Williams, suffered a broken bone and torn ankle ligaments after a low block in Seattle in Week 2 last year, and he still is recovering. Williams is on the physically unable to perform list and hasn’t practiced this offseason. Second-year player Mike Purcell filled in Friday. Quinton Dial and Tony Jerod-Eddie also are options at the position.
The 49ers also have lost running back Kendall Hunter (ACL) for the season and running back LaMichael James (elbow) for several weeks. On defense, the team could start the season without two starting linebackers. NaVorro Bowman still is recovering from his ACL injury, and Aldon Smith is facing a possible league suspension.
Dorsey, who celebrated his 29th birthday on the day he was injured, is in the final year of a two-year contract. The 49ers don’t use a nose tackle when they are in their nickel defense, which they play on nearly 60 percent of their defensive snaps.
Hyde is No. 2 running back – Friday’s practice included the first “live” tackling session of the offseason, a first-and-goal drill that mostly incorporated running plays.
When the second-team offense was on the field, running backs Jewel Hampton and Alfonso Smith got the carries. When the first-teamers got their chance, the tailback was Carlos Hyde. None of them scored; the 49ers’ defense won the session overall.
The 49ers didn’t use Frank Gore, their top runner, because they aren’t going to risk a tangle-in-the-pile-type of injury during training camp. The sequence suggested what everyone assumed when Hunter and James went down with injuries: Hyde is now the top backup, and there’s a good chance he will start Thursday’s preseason opener against the Ravens in Baltimore since he’s listed behind Gore on the team’s depth chart.