The Rays agreed to a minor-league contract with Slater on Monday, Ryan Bass of Rays.tv reports.
The veteran outfielder elected free agency after being designated for assignment by Tampa Bay in mid-June, but he'll rejoin the organization on another minor-league deal. Slater played in just seven games with the Rays and went 6-for-22 (.273 average) with two doubles and three steals. He also had stints with the Marlins and Mets early in the season, and he combined to post a .518 OPS in 21 contests between those two clubs.