Pires declared he would not be joining the Union because Philly is "not a beautiful city".
Union coach Peter Nowak told philly.com: "I will say some have very little understanding of the rules of the league and its single-entity structure.
"People need to understand the rules before they open their mouth. Also, I think he is looking at cities like Chicago, New York, Miami and Los Angeles and thinking Philly is a small town compared to them. There are a lot of guys [who think] like this, where except the four major [cities], they don't know much about the U.S.
"When you come to the U.S., you are trying to mold and improve the game as much as possible. [Former MLS] players like myself, Marco Etcheverry, [Carlos "El Pibe"] Valderrama and [current D.C. United's] Jaime Moreno realized that they aren't just here to better their team but to help raise the profile of the sport. Mr. Pires is supposed to come here and promote soccer, not worrying about being in a vacation resort in some 'beautiful' city."