Pat Rafter had one piece of advice for Nick Kyrgios and Bernard Tomic

IT’S not the discipline or the attitudes. Pat Rafter’s got a very different take on what’s holding Nick Kyrgios and Bernard Tomic back.

Australia's tennis captain Pat Rafter (R) chats with team member Bernard Tomic during a Men's singles match against Ze of China during the 2011 Davis Cup Tennis Tournament's Asia/Oceanic Zone Group I second-round tie in Beijing, China 08/07/2011.

THERE’S been plenty of debate surrounding what Aussie young guns Nick Kyrgios and Bernard Tomic need to do to fulfil their potential and take the next step in their tennis careers.

The two have copped a fair amount of criticism in the early stages of 2016. Tomic’s attitude was slammed after he withdrew from a match during the Sydney International because he wanted to focus on his preparation for the Australian Open, while he has also become involved in a verbal to-and-fro with 17-time grand slam champion Roger Federer.

People have been lining up to lash Kyrgios after he blew up at the chair umpire in his loss to Tomas Berdych, and he only narrowly avoided a fine for answering his phone on the court during a mixed doubles match.

But forget those discipline and attitude issues. Two-time US Open winner Pat Rafter has a different opinion on just what’s holding the two back.

Speaking on SEN radio on Wednesday evening, Rafter said the pair’s fitness levels weren’t up to scratch, but if they were to improve that aspect of their game, they could be anything.

His comments came after Lleyton Hewitt and Andre Agassi’s old coach Darren Cahill said Tomic was conserving energy during his matches — the result of continuous gruelling practice sessions with his father and coach John Tomic.

“Darren’s exactly right, these guys and Nick to an extent, they conserve energy because they aren’t fit enough and once these guys get fit they’re going to be powerhouses in the game,” Rafter said on SEN’s The Run Home.

“If you don’t get fit you’ll have to continue to conserve energy and that means throwing games, throwing points, throwing certain situations in the match, so you can get through a five-set match. If it’s hot conditions it’s going to be very tough as well.

Rafter imparting some wisdom on nick Kyrgios.

“Maybe it has something to do with the training. I don’t know when he (Bernard) was with his father, but I can’t really comment on that. I didn’t really see any of it.

“Darren knows what he’s talking about, you won’t get any better analysis from anyone than Darren.”

Now Tennis Australia’s Director of Performance, Rafter said he hoped the appointment of Hewitt as Davis Cup captain — a post he himself held before taking on his current role — would inspire the next generation to match the 34-year-old’s famed work ethic.

“I’ve watched a lot of kids come through the Davis Cup system and the player development side of things and they’ve got to see Lleyton, see him train and they’ve got to see his attitude around the Davis Cup and how passionate he is,” Rafter said.

“It hasn’t quite rubbed off, which I’m a bit surprised with, because he does set a really good example.

“I’ve been really interested to see that, I thought they would’ve taken on a bit more.

“It will be interesting to see how (Lleyton) goes with the DC job, he’s got these young guys who look up to him and hopefully he can have a really good impact on them, because in time they will mature.”

Rafter’s relationship with the brash youngsters hasn’t exactly been without its road bumps.

After Tomic’s third round loss at Wimbledon last year, he launched an extraordinary attack on Tennis Australia for failing to support him, claiming Rafter was “a good actor” and “a mask”.

Kyrgios fired back at the Australian legend on Twitter in July, calling him “negative” and saying, “Does this guy ever stop?” when Rafter took a swipe at the younger generation’s “sense of entitlement”.