Zimmerman, 22, was drafted in the third round of the MLS draft by the New York Red Bulls earlier this year, and appeared in seven games for the Red Bulls in the 2009 season. He was one of 12 players left unprotected by the side for the expansion draft.
Zimmerman was one of four players with local ties to be left unprotected by his club, but the only one selected. FC Dallas' Anthony Wallace and Blake Wagner, both local products were available, as was the L.A. Galaxy's Yohance Marshall, who attended South Florida. Former Plant standout Bobby Boswell and former Hillsborough County United standout Jeremy Hall were both one of the 11 players protected by the Houston Dynamo and New York Red Bulls respectively.