Mardy Fish woke up ill just a few hours after losing the match that knocked him from the Sony Ericsson Open in Key Biscayne, Fla.
Two doctor check-ups later, Fish was diagnosed with fatigue. He was told he needs rest.
The World No. 9 and top-ranked American has withdrawn from this week's Davis Cup action against France in Monte Carlo. The USTA is calling it a "minor health scare."
Fish had a disappointing start to the 2012 season, not making it past the second round of any tournament until the Sony Ericsson, where he reached the quarterfinals before losing to Juan Monaco, 6-1, 6-3. From the AP:
"We don't want to get exactly into what the symptoms were. He didn't feel normal. He said, 'Hey, something's wrong here.' He was concerned about it," Fish's agent, John Tobias, said in a telephone interview Monday. "His body got out of whack, caused by a number of different variables ... (but) they ruled out any potential long-term issues."
Ryan Harrison will serve as Fish's replacement. Harrison was a part of the lineup in the U.S. team's last Davis Cup action when they swept Switzerland. Harrison was not even on the practice squad prior to Fish's illness.
"We're just going to scale (Mardy) back a little bit and make sure that he arrives at a tournament well-rested and ready to compete," Tobias said. "His commitment to Davis Cup is like none other. It's absolutely killing him to miss it this time."