Fifteen players off the 49ers' 90-man roster began practice Thursday on the side field unable to practice due to injuries.

Inside linebacker NaVorro Bowman who aggravated a groin strain and Patrick Willis sporting a black cast on his broken right hand were among the players who did not suit up for practice.

Five wide receivers -- Michael Crabtree Mario Manningham Kyle Williams A.J. Jenkins and Kassim Osgood -- did not practice. Another receiver Quinton Patton is not able to catch passes due to a soft cast to protect an injured middle finger on his left hand.

Outside linebacker Aldon Smith and center Jonathan Goodwin also did not suit up for practice due to unspecified injuries. Rookie tackle Carter Bykowksi who left practice early Wednesday is also not practicing.

In addition to Crabtree and Manningham there are five other players who are on active PUP or non-football injury: Running backs Kendall Hunter (Achilles) and Marcus Lattimore (knee) defensive linemen Tank Carradine (knee) and Quinton Dial (toe) and tackle Luke Marquardt (foot).