Waratahs' Barnes to have thumb surgery - Sydney Morning Herald

AAP

Wallabies playmaker Berrick Barnes will be out of Super Rugby action for up to six weeks after undergoing surgery on Wednesday to have a wire inserted in his dislocated thumb.

The NSW Waratahs' utility suffered the injury making a tackle in the 17th minute of his side's loss to the Cheetahs last Friday - his first appearance of the Super Rugby season after missing his team's three earlier matches with a knee injury.

There's further gloom for the Waratahs, who have slumped to a 1-3 record in 2013, with Wallabies hooker Tatafu Polota-Nau (hamstring) and No.8 Wycliff Palu (ankle) both also expected to miss Sunday's clash with the Blues in Sydney due to injury.

However team officials are hopeful they'll be back for the following game against the Hurricanes in Wellington.

Senior Waratahs figures insist their struggling side can still catch runaway Super Rugby leaders the Brumbies, despite conceding a huge early advantage to the Canberra-based franchise.

The Brumbies lead the overall table by six points and are 10 clear of their closest Australian conference rivals Queensland, who have played one more game.

The Force, Rebels and Waratahs are all 14 points behind the Brumbies, with NSW last on points for and against.

"The Brumbies can be caught, nothing is ever sure in rugby," Waratahs assistant coach Alan Gaffney told AAP.

"We will be chasing them."

NSW skipper Dave Dennis said the Waratahs were more than capable of reeling in the Brumbies.

"We haven't started so well, but it doesn't rule everything out," Dennis said.

"We still have to play them again, which will be a key game."

Gaffney said the Waratahs remained a work in progress and it would take time for them to throw off the attacking shackles of previous years.

"Some players have been regimented in the way they've played over a period of time," Gaffney said.

"But now they are being given a lot of freedom.

"As yet, we haven't totally seized that freedom, but it will happen."

NSW face another testing task on Sunday against a resurgent Blues side who have won two of their three games and are running fourth overall.

"They have plenty of new faces who are hungry to play and they pose plenty of threats across the field," said Dennis.

"That area of execution and holding onto the ball is going to be key this week, because if we don't, there's plenty of guys in their team that can punish us."