NSW Waratahs coach Chris Hickey feels he has the back-up to cover injured star Berrick Barnes if he's ruled out for the start of next year's Super 14.

Barnes is heading home from the Wallabies base in Japan after being scratched from the grand slam tour of the UK and Ireland with a serious ankle injury.

Scans revealed Barnes suffered a serious syndesmosis injury to his left ankle in training on Thursday, meaning he could face surgery and several months of rehabilitation when he returns to Australia on Sunday.

The inside centre has joined the Waratahs on a one-year deal for the 2010 Super 14 campaign from Queensland, but Hickey was remaining positive despite the bad news from Tokyo.

"Our doctor has spoken with the Wallabies medical staff and obviously its serious enough to send him home," Hickey told AAP.

"He'll see our doctor, we'll scan him and see where he's at. Work out what the next step is, whether it's surgery or whether it's just a rehab program to get it right."

Surgery could have Barnes sidelined until at least March, meaning he would definitely miss the start of the Waratahs' Super 14 campaign - including their round two and three matches in South Africa.

But Hickey feels even without experienced backline stars Lote Tuqiri and Timana Tahu, he has the players to replace Barnes.

"You always want your best players to be available but we're fortunate we've got some good depth," he said.

"Both Daniel Halangahu and Kurtley Beale, who played 10 for us during this year's campaign. We'll fill that gap without any concerns for us.

"We're just fortunate that we've got some depth and players that can cover both 10 and 12 if Berrick doesn't get back on board until perhaps March."

Hickey was unsure whether Barnes would stay in Sydney during his rehab or head back to Queensland, saying a lot would depend on what their medical assessment reveals.

"It's difficult to say at this stage until we get him assessed medically," he said.

"Worst case scenario, it could be four to five months if it requires surgery, but hopefully that may not be the case.

"Obviously if we're going to supervise his rehab then we'll need him close by but whether he's injured or not he would have had some leave.

"I'm sure he'd want to spend some time back home with his family. They're all things we'll sort out once he's back here."