The 36-year-old is expected to start for the United States at this year’s World Cup. His play has been a major reason in Moenchengladbach’s rise to seventh place this season.
"Kasey has been outstanding Moenchengladbach coach Horst Koeppel said after Wednesday’s announcement. "I prefer to say defense is a team effort but he alone has won us points."
Keller was voted the club’s best player by Moenchengladbach fans during the first half of the season and was selected the U.S. National Team’s player of the year in 1999 and 2005.
He has spent 15 years in Europe starting at Millwall in 1990 when he became the first American to play in England on a U.S. passport.
Keller also played for Tottenham Hotspur and Southampton and at Rayo Vallecano where he became the only American to compete in Spain’s La Liga.