Per Henry Schulman the Rays are apparently interested (again) in their former closer:(Hat tip to MLBTR)

Tampa Bay, concerned about the health of Troy Percival, has some interest in trading for Tyler Walker, a source said. The Giants dealt Walker to the Rays in 2006. He saved 10 games for the Rays before blowing out his elbow

Walker is boasting a career high GB/FB ratio of 1.32 and has a career average just over 1. 45% of the balls put into play have been on the ground, encouraging yet his nearly 16% HR/FB ratio is terrifying. He's not a relief ace by any means, and I don't know how much of an upgrade he'd be over some other internal options.