Rafael Nadal advanced to the fourth round at Indian Wells on a walkover in California. The former world No. 1, playing his fourth tournament since returning last month from a seven-month injury absence, was preparing to take to the court when he learned third-round opponent Leonardo Mayer of Argentina had pulled out with a bad back. Mayer's sudden withdrawal left Nadal feeling a little flat, but the Spaniard was quite animated when describing the earthquake, which originated from an epicentre just 30 miles from Indian Wells. Nadal, who is playing his first hard-court tournament since a sore left knee forced him out of the semi-finals at Miami last March, said he wouldn't put in a lot of extra practice, but would work out in the gym.