The Tennessee Titans have decided to keep Martin on the physically-unable-to-perform list for the rest of the season after the rookie practiced with the team the past three weeks.||||||| Martin was the Titans' sixth-round draft selection out of Oklahoma State. The 6-foot, 207-pound safety struggled with injuries during the offseason and started the season on the physically-unable-to-perform list. Coach Mike Munchak said Monday it's been hard to get a feel for Martin who had been limited even the past couple of weeks.