He was a member of the Cleveland Browns, Hartford Colonials, New York Jets, Montreal Alouettes and the Toronto Argonauts.

Jennings was promoted to the active roster on October 3 after the team placed James Davis on the injured reserve list.

[4] He made his NFL debut October 4, 2009 for the Browns against the Cincinnati Bengals running for 8 yards on 1 carry.

On December 10, Jennings became the first Browns rookie running back to score a rushing touchdown since Lee Suggs in 2003.

[7][8] The Browns decided not to re-sign Jennings, who threatened to seek out other opportunities, despite injuries that plagued running back Peyton Hillis.

[6][9] Jennings carried the ball only 12 times for 6 yards in his tenure with the Colonials however he was an important contributor to their special teams unit.