Did Dan Marino retire with the Lions?

[BD Sullivan]

When Jim Brown retired right before 1966 training camp, the Browns just put him on a reserve list in the event he changed his mind. In 1972 (I think), George Allen got the idea of claiming Brown, considering he was still only 36 at the time. The Browns quickly made sure he didn't end up elsewhere, and there's no indication that Brown was thinking of a comeback--until 1983.

[Reaser]

When Jim Brown retired right before 1966 training camp, the Browns just put him on a reserve list in the event he changed his mind. In 1972 (I think), George Allen got the idea of claiming Brown, considering he was still only 36 at the time. The Browns quickly made sure he didn't end up elsewhere, and there's no indication that Brown was thinking of a comeback--until 1983.

Deion Sanders wanted to come back to play for the Raiders and the Redskins even released him off their reserve/retired list but he had to go through waivers and the Chargers (Marty) claimed him.

Which is a good example of why it mattered if you retired under contract with a team or as a FA.