Rugby: Kerr Barlow, Clark and Barrett train with All Blacks

Tawera Kerr-Barlow in action for the Chiefs. Photo / AP.

Chiefs halfback Tawera Kerr-Barlow and his Super Rugby teammate Craig Clarke are training with the All Blacks ahead of Saturday's Rugby Championship opener against the Wallabies in Sydney.

The pair played starring roles in the grand final victory over the Sharks in Hamilton a fortnight ago and their good year has continued, with Kerr-Barlow called in to train with the All Blacks today and tomorrow and Chiefs lock and captain Clarke involved with the squad after getting his knee checked by the national team's medical staff.

Kerr-Barlow was named in the training squad for the Ireland tests in June but has since missed out to Aaron Smith and Piri Weepu. There is no doubt now that the All Blacks selectors regard the youngster who turns 22 on Wednesday as the third best halfback in the country.

"He's had a great year and we were just a little bit short of players to defend against," said assistant coach Ian Foster of Kerr-Barlow's involvement. "Also with Tawera, we saw it as an opportunity to bring him in and have a look. I think he'll learn lots but he has plenty of energy and is a player on the rise.

"We've only got two nines in our squad and you're one injury away from someone having to come on to the bench or into a starting position so either way it's important that he knows a little bit about what we're doing."

Barrett was also named in the June training squad but has made way for Dan Carter and Aaron Cruden, with Foster saying it was ideal opportunity to give him a refresher course in the All Blacks' methods.

"It was a chance to give him a couple of days early in our camp to keep it fresh in his mind what we're doing. With Clarkey I think it's just a chance to keep looking at his knee, to get another assessment on it."

Clarke will be boosted by the inclusion. It is the first time he has been involved with the All Blacks and it suggests that he has overtaken Jarrad Hoeata in the selectors' minds.

For backs' coach Foster, one major loose end has been tidied up with the announcement that second-five Sonny Bill Williams has been cleared by his new Japanese club Panasonic to play for the next two games.

"When you know there's going to be a few complications you just sit back and relax a bit so we've just been waiting. But the fact that he's here training today and was here last night is fantastic, we've got a full week's preparation.

"He's pretty excited, it was part of why it was an easy decision to make [to include him]. He reached good levels in June and I'm sure he wants to do that in the next two weeks."

One of the selectors' most difficult decisions will be on the left wing, with Julian Savea, Hosea Gear and Ben Smith vying for the position. Cory Jane, now free from his ankle injury, is likely to be named on the right wing.