MLS's website has an article regarding Preston Zimmerman resurrecting his career in Germany with Mainz's reserve team. It got me to think about many of the US born players who forgo MLS following high school or college to play in Europe. Zimmerman has been able to play for some well respected clubs in Germany and Austria, but he has never played first team football in Germany; though he played 21 games in Austria for Kapfenberger SV's first team. At 22-years old it seems he is one player who should return to the US and have a go in MLS. However, would he be successful in MLS or is MLS's cutthroat management style a hinderance to players like Zimmerman.
Last season, we saw Sal Zizzo return to the US when he signed with MLS and was allocated to Chivas USA. Zizzo did not have much success in Europe, most notably playing eight matches for Hannover '96 in Germany. He played 10 matches for Chivas USA last season scoring no goals for an extremely awful team.
I'm not sure these US players who leave early can be successful if they move to MLS following stints in Europe. We've seen Danny Szetela move to Europe before returning to MLS two years later. Upon return he played four matches for DC United before being released. According to Wikipedia he is a free agent still. At one time Charlie Davies could have been considered the most successful US player to skip MLS and go to Europe following college. However, after his car accident I don't think the same can be said.
I find it interesting we see every year MLS teams unable to sign high school and college players who move abroad. As in Zimmerman and Zizzo, perhaps moving too early has hurt their careers when they should be getting pro experience in their home country's domestic league. These players also flatten out talent-wise and are no longer the best player on their teams which also needs to be considered; and they stop developing.