Redman was released by Pittsburgh last October after playing three games. He said Friday on Twitter that he tried to play through a neck injury before the club let him go.
"To those who are wondering why I am not playing anymore," Redman wrote Friday. "Last season I tried my best to play through a neck injury but I just wasn't myself on the field.
"After being released I went (to) Cali to see Dr. Watkins (doctor who did Payton [sic] Manning's neck surgery) after 2 MRI's and a cat scan he then told me I had suffered a career ending injury to my spinal cord. Various teams have called but as you can see I was unable to go. I would like to thank all my fans for the tremendous support throughout my career."
Redman spent five seasons with the Steelers and was the starting running back heading into last season. He made one start before playing two games off the bench and had just 12 yards on 10 carries.
In 50 career games, the Bowie State product ran for 1,148 yards with five touchdowns and caught 50 passes for 408 yards with two scores.