PARIS (AP) Gael Monfils has been ruled out of France's Davis Cup semifinal in Croatia this week.

Coming off the U.S. Open semifinals, Monfils was hampered by a knee problem, the French Tennis Federation said on Wednesday.

It's another big blow for the French team after Jo-Wilfried Tsonga was forced to pull out last week because of a knee injury, and was replaced by Richard Gasquet.

Lucas Pouille and Gasquet are now expected to play the singles. Pouille has played only one tie for France, beating Jiri Vesely in the 3-1 quarterfinal win against the Czech Republic. Nicolas Mahut and Pierre-Hugues Herbert, the world's top-ranked doubles pair, complete the lineup for the semifinal in Zadar.

France is trying to reach the final for the second time in three years.