Both veterans will likely get a shot at making Tampa's 40-man roster.
Fontenot, 32, spent most of 2012 in a back-up role for the Philadelphia Phillies, but was dropped from the roster by the club in August after hitting .289/.343/.340 in 47 games. The seven-year big-league veteran is a career .265/.332/.401 hitter, but has seen his playing time decline each of the last three seasons.
Thompson, 33, was one of the feel-good stories of this past season, getting his first chance at big-league action since 2004 and a second chance to notch his first MLB hit – which he got on May 17 against the Red Sox. Thompson hit just .091/.167/.091 overall in his brief 23-game stint with the Rays, collecting two singles and six stolen bases.