February brings the dog days of tennis - a scattering of minor events as the players build up to the gourmet meals and bulging pay-packets of Indian Wells in early March.It is the perfect time, then, for a big name to sneak back on to the fringes of the tour. The 250-point tournament at Delray Beach in Florida is not often attended by grand-slam champions, but the unfortunate Denis Kudla (world No65) must have done a double-take at the identity of his first-round opponent: 2009 US Open winner Juan Martín del Potro.Five years ago, Del Potro inhabited the space that Stan Wawrinka has since moved into. He was the wildcard with the even wilder forehand - a 6ft 6in hurricane with the ability to blow Roger Federer backwards off the court.But he also had an achilles heel, or rather two achilles wrists - troublesome tendons that have required four operations.At 27, Del Potro still has the time and the talent to climb the mountain again. But can his body sustain him? He sailed past Kudla 6-1 6-4, but he did resemble a man playing - almost literally - with one hand tied behind his back.To see a great athlete brought low by chronic injury is always maddening, but how much more so when that athlete is charismatic and charming, with soaring approval rates both among tennis lovers and his locker-room peers.Yes, he is a talent, but that's not the main reason he enjoys support. As his friend and former rival Mardy Fish said: "He's just an awesome guy." ..