Rafael Nadal is back - and it's all about his back. Top-ranked Nadal injured his back warming up for the final of the Australian Open almost three weeks ago, eventually losing against Stanislas Wawrinka - a match he was an overwhelming favorite to win. Nadal has practiced little since then, getting treatment at home in Mallorca. He made a comeback last season from a left knee injury, which kept him out of the 2012 London Olympics. More...