Wide receiver Hank Baskett was released to make room for Bell, who originally signed as a free agent with the Bills. Bell amassed 6,728 rushing yards and 88 touchdowns at Wayne State and won the Harlon Hill Trophy, as the best player in NCAA Division II, after running for 2,084 yards and 29 touchdowns as a senior.
Baskett, who joined the Eagles as a rookie in 2006 and re-signed during the offseason, was active for the first two games but had no receptions.
The Eagles also announced Tuesday they have released safety Chip Vaughn and running back Martell Mallett from their practice squad.
The Associated Press contributed to this report.