Mets right-hander Steve Trachsel left the team Saturday to fly home to California because of family issues and was scratched from his scheduled start in the regular season finale. Left-hander Oliver Perez will replace Trachsel (15-8) against the Nationals on Sunday. The NL East champions weren't sure when Trachsel will return. "We'll probably have a workout on Tuesday, so hopefully he'll be back by then. But it's not certain," Mets spokesman Jay Horwitz said.