Nava, 32, has spent his entire career with the Red Sox, hitting .267/.357/.387 with 23 home runs in 424 major-league games. He was a key contributor on Boston's 2013 championship team, when he posted a .303/.385/.445 line and twelve home runs while appearing in 113 games as the team's primary right fielder. Nava has struggled to a .152/.260/.182 line in 29 games with the Sox so far this season, and was forced out due to the team's glut of outfield options.
For Tampa, Nava will provide depth behind John Jaso, Kevin Kiermaier, Brandon Guyer and Grady Sizemore in the outfield, filling the void left open when the team traded David DeJesus to the Angels before the non-waiver trade deadline. Nava can also play some first base, providing an alternative option to James Loney and Jaso down the stretch.
Nava is under team control through the 2017 season for a reasonably low cost, so he could turn into an effective pickup for the Rays.