The Flyers acquired Prospal, 33, from the Lightning in February in exchange for defenseman Alexandre Picard and a 2009 second-round pick.
Prospal, a free agent, recorded four goals and 10 assists in 18 games for the Flyers last season. He added three goals and 10 assists in 17 playoff games. Prospal has 179 goals and 375 assists in 792 games over seasons with five teams.
"Vinny really didn't express much of an interest in coming back and playing for us next season," Flyers general manager Paul Holmgren said. "His heart is elsewhere."
The Flyers will receive Nashville's 2008 seventh-rounder from Tampa Bay and a conditional pick in 2009.