What's the trope for...

A well-known player from a high-tier sports team who decides to play for a lower-tier team, either For the Lulz or he wants to be The Obi-Wan for his new team, but it's not because his old team was a group of consummate puppy-kickers, but rather that Victory Is Boring. Is it Defector from Decadence or something else?

I think Lost And Found is the place for you to ask that question.