This is a little confusing only because you have to pick 2 of the same object and apply actions and you need a kind of workaround. For example if object A passed to object B you could say set A inactive and set B active, but because they are the same object and you need to pick both the active and inactive player then the picking is a little more difficult.
My approach would be ball on collision with player (where player is set to inactive), grab this instance ID so lets say it is player01. Then you set all players to inactive, then you use system pick all players to open them all up to being picked again (this is required as when you did the initial on collision event you narrowed the player to one instance), then finally you pick player where id is 01 and set them to active! This is all in one event done with sub events.