The actor who played Coach did another show at the time he shot the Pilot for New Girl. So he was under contract that if that show got renewed for another season that he would have to take that job over New Girl. In short the show did get renewed so he had to go back to that show.
However the writer of New Girl has mentioned in an interview that she has left it open for Coach to make possible guest appearance in the series if he can.
Coach Moved Away and Winston got back from Afganistan I think and needed a place to stay so Nick and Shmidt got him at the airport
posted over a year ago
The show explaisn that Winston originally lived with the guys but got scouted to be on a basketball team in Latvia, so the apartment was sublet to there friend Coach until Winston returned.
