Martin (hamstring) was a non-participant at practice Thursday, Jenna Laine of ESPN.com reports.
Listed as such on the Buccaneers' first injury report of Week 5, Martin was joined by fellow running back Charles Sims, who is tending to a knee concern himself. Both players appear to be trending toward DNPs on Monday at Carolina, but there are two practices left for one or the other to stake a claim to the No. 1 spot in the backfield. If neither does so, Jacquizz Rodgers and Peyton Barber are the two healthy running backs in Tampa Bay.