More details of what prompted the row between Roger Federer and compatriot Stan Wawrinka at the ATP World Tour finals in London have emerged, with Federer's "feisty" wife, Mirka, blamed for sparking the dispute.
Video apparently showing Mirka heckling Wawrinka from the player's box and calling him a "crybaby" during his three set defeat to Federer has emerged as the two men try to patch up their differences ahead of Switzerland's Davis Cup final against France.
The pair were apparently involved in a ten-minute stand-up row after the match as a result of the heckling, which prompted an angry response from Wawrinka at the time, with umpire Cedric Mourier begging him to calm down. He also appears to look at Federer as he asks: "What did she say?"
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Wawrinka was "agitated by Mirka's habit of shouting out encouragement for her husband between first and second serves, in a breach of tennis etiquette", reports the Daily Telegraph.
In addition to his reaction in the video, The Times says that Wawrinka also complained: "She did the same thing at Wimbledon."
The presence of Swiss Davis Cup captain Severin Luthi in Federer's box – he is one of his coaches – may also have irked Wawrinka, notes the Daily Mail.
The incident took place as tensions ran high at the O2 after Wawrinka wasted three match points during his epic showdown with Federer.
Neither player has spoken about the incident and they appear to have patched up their differences, at least in the short term, with both looking forward to the Davis Cup, the only major trophy Federer has not won during his career.
Wawrinka, though, exacted a small measure of revenge by making a bunny-ears geture behind Federer's head as they posed for a picture with the rest of the Swiss team, and posted on Federer's Twitter account, after arriving in France.
It's great being with the boys again .. And #captain #lüthi pic.twitter.com/iMWJUVKd0T— Roger Federer (@rogerfederer) November 17, 2014
"The pair used to be close friends and Wawrinka credited Federer with aiding his development," reports the Times. "However, Wawrinka's rise up the rankings has changed the dynamic. He is also a complicated soul with a Samuel Beckett tattoo to prove it, and it remains to be seen how he will react this week.