sentences:  In 1991 he moved to Strasbourg whom he helped win the 1995 UEFA Intertoto Cup, scoring a hat-trick in the second leg of the final against FC Tirol Innsbruck.In 1996 he moved to Germany to play for Karlsruher SC.Keller was signed by West Ham in July 1998 on a free transfer from Karlsruher SC by manager Harry Redknapp.