Rafael Nadal has criticised the decision to play the Olympic tennis tournament over the best of three sets rather than the five sets employed at Wimbledon and other Grand Slams. Nadal kicked off his bid for a third Wimbledon title with a 7-6 (7/0), 6-2, 6-3 victory over Brazil's Thomaz Bellucci, but the world number two will need to take only two sets to win a match when he returns to the All England Club for the London Games next month. While that would seem to make it even easier for the Spaniard to dominate at the venue where he has reached the Wimbledon final on his last five appearances, Nadal -- who won gold in the men's singles in Beijing four years ago -- actually fears it will turn the Olympic event into a lottery. On the day the 64 competitors for the men's Olympic tournament were announced, Nadal claimed the combination of playing three-set matches on Wimbledon's fast grass courts was a bad idea. Only the men's singles final will be played over five sets and Nadal said: "It's great to have the Olympics here in Wimbledon, but playing best of three sets on grass in a very important competition makes the tournament more difficult for everybody because there are no favorites then. "That's makes the tournament a little bit more crazy. Everybody can win even more than on hard or clay, because playing best of three sets, the match can be decided in just a few points. "So that's probably the negative thing. In every match, you are at the limit. "I don't say it's a 'crazy idea'. But it is a little bit more difficult to predict what's going to happen." Nadal wasn't the only former Wimbledon champion grumbling about the Olympics on Tuesday as Australia's Lleyton Hewitt also launched an attack on the tournament organisers for failing to give him a doubles wildcard. Hewitt, who won Wimbledon in 2002, has been handed a wildcard for the singles, but the 31-year-old and partner Chris Guccione weren't given the same courtesy for the doubles. "Yeah, I am disappointed. I can't work that out for the life of me. I guess playing as much Davis Cup as you do doesn't count for everything," said Hewitt after his 6-3, 6-4, 6-4 defeat against France's Jo-Wilfried Tsonga in the first round at Wimbledon.