So the collective bargaining agreement between the league and the players' union mandates the league name 32 players to the MLS all-star team each year.
In order to fulfill that requirement, the league released a list of "inactive" all-stars and noted snub Kenny Cooper made the list. Just like that, viola, Cooper is an all-star. Not that he shouldn't have been in the first place -- how do you keep the league's second highest scorer off the team? -- but his inclusion is largely a technicality.
Thankfully, the Red Bulls get all the advantages of having a number of guys named to the all-start team with (nearly) none of the drawbacks. Heath Pearce isn't playing, so he won't risk re-injuring himself, and now Cooper is in because of the union contract. The only Red Bull playing tonight in PPL Park is Thierry Henry and he shouldn't play the whole game.