You only need to take one look up at Will Skelton's giant frame to recognise he's a Wallaby in the making, but the NSW Waratahs enforcer says he must pass an important test against Queensland in Saturday's Super Rugby derby at ANZ Stadium.

The Reds boast incumbent Australian locks James Horwill and Rob Simmons and 21-year-old Skelton recognises this is his first acid test on the road to an international debut.

Despite only starting his first Super Rugby match in Sunday's emphatic win over the Western Force, Skelton is confident he'll be ready if called upon by Wallabies coach Ewen McKenzie this season. And if Skelton continues on from his bulldozing start against the Force, there's every chance a Test debut won't be far away.

If fit, inspirational leader Horwill shapes as a certain starter, but otherwise Australia's stocks in the lock position are in need of a boost. At 203cm and 135kg, Skelton has the size, and he's eager to prove against the Reds that he also has the substance.

"If called upon, yes [I'm ready for the Wallabies]," said Skelton. "But at the moment I'm just worried about the Waratahs, just trying to establish myself in the starting 15.

"100 per cent [Horwill and Simmons will be a challenge]. Every week I look at it as a test because it's a massive challenge playing against seasoned guys ... like Wilhelm Steenkamp [Force].

"They're awesome players and guys I'll always strive to be like, but I know I'm a different player and hopefully I can bring another personality to my team and bring that out on Saturday."

However, with South African international Jacques Potgieter lurking on the Waratahs bench, Skelton is taking nothing for granted. The Hills Sports High product was disappointed with some turnovers and missed tackles in the win over the Force and is putting pressure on himself to improve for the Reds.

NSW have a major size advantage over their Queensland counterparts, but Skelton says they need to work hard to make sure it counts.

"We've got a big pack and we want to dominant up front especially in the set piece - the scrum and line-out - that's our game," he said. "They're very fast, agile and very good with the ball. Guys like Jake Schatz and their locks are very mobile so we've just got to stick to our systems and our shape and hopefully we can get the result."