Wales coach Warren Gatland has told his Six Nations winners they need to get fitter if they are to defeat the southern hemisphere superpowers.

Wales were beaten twice by world champions South Africa last month but have the chance for revenge when they tackle the Springboks again as well as Australia and New Zealand at the Millennium Stadium in Cardiff in the autumn.

"We need to produce 30 world-class athletes. We probably have half-a-dozen players who need to improve physically to be able to compete with the best in the world," Gatland told the Western Mail newspaper.

"Our strength is good, but some players need to get bigger, while others need to get a bit leaner to help them be more mobile around the pitch.

"Those are things we're working on physically. It's about building depth and having a playing base."

Gatland admits that his team, who clinched the Grand Slam in March, were brought back down to earth three months later by South Africa.

"We went to South Africa thinking that where we finished after the France game was where we were going to carry on from," admitted the coach.

"That wasn't the case. We needed to concentrate more on the basics and go back over the starting points in preparation for the first Test. I assumed we were further ahead from the time we had spent together in the Six Nations, but you have a break and the players regress a bit or forget a few things.

"Going forward to November, when we come together as a squad, we'll work hard on the basics again and what we're trying to achieve."

Wales beat Australia in 2005, but have only defeated South Africa once, in 1999, and have not got the better of the All Blacks since 1953.

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