Last Friday's verbal showdown between Andre Agassi and Pete Sampras has been described by world number one Roger Federer as an “awkward moment” and “a bit unfortunate”. The episode occurred during the “Hit for Haiti” charity doubles match at the Indian Wells Tennis Garden where Sampras took exception to Agassi's suggestion he was a poor tipper. Each of the players competing wore a microphone so the crowd and television viewers could hear the banter and Agassi repeated the allegation he had made about Sampras in his autobiography ‘Open'. “There was definitely an awkward moment, a bit of a heated moment,” Federer told reporters on Sunday. “It's a bit unfortunate, but that stuff kind of happens. It's a pity if that's what grabs the limelight and not the event itself, you know.” After Sampras and Federer had taken the lead, the American celebrated with a fist bump, prompting Agassi to reply: “You always have to get serious, huh Pete?” Sampras countered: “Okay Andre, I'll joke a little bit. I'm going to imitate you.” He then mimicked Agassi's bow-legged shuffle. In response, Agassi turned his pockets out and said: “I don't have any money. No, wait, I've got a dollar” The back-and-forth continued, Sampras at one point saying: “If that's the way you want to play it”, and Agassi responding: “It's better than being a valet driver and you pulling up.”