World number nine Mardy Fish has pulled out of the United States' Davis Cup quarter-final against France, who will be without world number 14 Gael Monfils for this week's tie.
Fish had a health scare on Thursday in Miami after suffering extreme fatigue and was told by doctors to rest, the U.S. Tennis Association said on their website (www.usta.com) on Monday.
World number 66 Ryan Harrison replaces Fish in the squad.
Monfils misses out with a stomach injury.
Captain Guy Forget has not yet named a replacement, the French tennis federation said in a statement.
Jo-Wilfried Tsonga, Julien Benneteau and Michael Llodra are the other players already in the side for the tie starting on Friday on the claycourts at the Monte Carlo Country Club.
