Lee last played in the NHL in March of 2013, but was sent down to the AHL to play with the Syracuse Crunch following a disappointing end to the Tampa Bay Lightning regular season in the lockout-shortened year. It was there that Lee tore his ACL, in the Eastern Conference semifinals versus the Springfield Falcons on May 17. He hasn't appeared in a professional game since.
The Lightning placed him on the injured reserve at the start of the 2013-14 season, where he remained until his contract with the Lightning expired on July 1. According to Pro Sports Transactions, he also retired officially on July 11, so you might call this a comeback.
Lee played 42 games across two seasons with the Bolts, scoring zero goals and recording 8 assists in 15:25 of average ice time with the Bolts. He won some fans early for his physical play, but never caught on in a permanent role with the Lightning as they switched coaches from Guy Boucher to Jon Cooper.
A tryout contract is the furthest thing from a real commitment, and with so many quality right-shot blue liners already rostered in Nashville, he'll be a depth option at best.