The Union and midfielder Vincent Nogueira have agreed to mutually terminate his contract. Nogueira had a guaranteed salary for this season of $400,000, the fifth-highest on the team.
The team announced that, due to personal health issues, Nogueira will return to France.
"I want to thank the Philadelphia Union for their understanding of my situation and wish my teammates well going forward," Nogueira said in a statement released by the team.
Nogueira, 28, made his last Union appearance in Wednesday's 3-2 U.S. Open Cup win over the Harrisburg City Islanders, playing 73 minutes.
Signed by the team on Jan. 30, 2014, he appeared in 58 games, making 64 starts and totaling nine goals and three assists although his main responsibility was as a defensive midfielder.
"We want to thank Vincent for his contributions to the club over the last two years, and we wish him the best both personally and professionally," Union sporting director Earnie Stewart said in a statement. "At this time it was our desire to enable him to be with his family at home in France."