A Leak is when you lose access to something that is no longer needed, therefore it exists in the game's memory forever. As long as you have access to tempPlayerGroup, it's not leaking.
Now if you were to create a NEW tempPlayerGroup, you would lose access to the old one, and the old one would be considered a Leak.
I would rename that variable from tempPlayerGroup to something else because "temp" implies that it's only going to exist temporarily (create/use/destroy), but you create it only once and use it for the rest of the game.