Rays manager Joe Maddon likes the flexibility Thompson will add to the bench while playing games in National League parks.
"He gives us speed off the bench," Maddon said. "The National League game in general puts another guy on the bench. The one thing that we could really utilize is to be able to steal a base or to be able to score on a double from first base later in the game."
Thompson, who was acquired in a trade with the Phillies on May 16, has hit .063 with one RBI, two runs scored and two stolen bases in eight games with the Rays this season.
"My numbers weren't great, but I felt like I hit the ball OK [while with the Rays]," Thompson said. "I've certainly gone through 16 at-bats and had worse results than that, so it's all relative, I guess. It was a small sample size. I wasn't really disappointed with how I hit the ball, but I certainly would have liked to have had a better outcome hits-wise.
"And getting out there to pinch-run and stuff like that, I've got to do that. So I think I got more at-bats on this team than the 25th man on a lot of other American League teams, so I was grateful for that."
Thompson is hitting .283 with 11 steals at the Triple-A level this season in the Rays' and Phillies' organizations.