'They deserve to be the big four but I personally really don't care'

French Open champion Stan Wawrinka feels completely comfortable about his failure to break into the unofficial big four of men's tennis despite winning two grand slam titles.

The Swiss stunned Novak Djokovic in the Roland Garros final this month to collect his second major crown and is seeded fourth at Wimbledon where he began his title bid with a 6-2, 7-5, 7-6 win over Portugal's Joao Sousa in the first round on Monday.

But people still talk of Djokovic, Roger Federer, Andy Murray and Rafa Nadal as the big four.

"I personally really don't care," Wawrinka told reporters. "For me the big four always mean the big four. They're good where they are because they did so much for the tennis and they were so strong during more than 10 years.

"They deserve to be the big four and they will always be the big four. That's for me how I see it."

Wawrinka, 30, won the Australian Open last year and teamed up with Federer to help Switzerland win the Davis Cup before ending Djokovic's career grand slam hopes with a stunning victory in the Roland Garros final this month.

"The mentality is the same as last year," he said.

"I know I'm playing well. I have a lot of confidence. It's a new year, new tournament. We all start from zero. We need to win match after match to go further in the tournament.

"I'm confident with myself, but I'm really careful with how mentally I get ready for every match."

Wawrinka will play Victor Estrella Burgos of the Dominican Republic in the second round.

"In general I feel good," he said. "I know where my game is. I feel ready for the next one."