ALLEN PARK, Mich. -- Detroit Lions running back Joique Bell has been cleared for physical activity, according to a team spokesman, but has been ruled out for Sunday's game against the Buffalo Bills.

The 28-year-old suffered a concussion against the New York Jets on Sunday and did not practice with the Lions all week, including during Friday morning's practice.

After being completely absent from practice Wednesday and Thursday, Bell was in attendance Friday, but was just running on the side.

Bell is the Lions' leading rusher on the season with 48 carries for 152 yards. He also has nine catches for 73 yards.

In Bell's absence, the Lions likely will give a larger workload to starting running back Reggie Bush along with potential carries for George Winn, who the team signed off their practice squad earlier this week.

Bell is not the only ailing Lions running back. Theo Riddick, who would have likely been in line to see some of Bell's carries, also has been ruled out after missing practice all week with a hamstring injury.