North Harbour's prospects of lifting rugby's Ranfurly Shield for the first time received a surprise boost today when All Blacks prop Tony Woodcock turned up for training.

A cornerstone of the Graham Henry's first choice test pack was only expected to be back from international duty for next weekend's top six clash at Waikato but the lure of Harbour's challenge in Christchurch on Sunday proved irresistible.

"He rang late last night and said `I'm in. I said you're joking!"' delighted Harbour coach Allan Pollock said today.

"There was no approach from the (North Harbour) union or the team management -- to have it come from the player, a call out of the blue says a lot about this team."

Pollock said he kept news of Woodcock's availability under wraps until he trundled into the Albany team room today.

"Quite a few of our players didn't know he was available. They were walking through the door going `what's he doing here?' The smiles were infectious."

Woodcock's desire to cut his post Tri-Nations break enables Pollock to field his complete All Blacks contingent, with Luke McAlister to start at first five-eighth and Greg Rawlinson at lock.

Canterbury also have two All Blacks available for selection -- fullback Leon MacDonald and second five-eighth Aaron Mauger.

Pollock said Woodcock was not short of motivation to play against Canterbury.

The front rower is one of the few survivors from Harbour's last shield challenge in Christchurch -- a 10-65 thrashing in 2002. McAlister and centre Anthony Tuitavake were also party to that nine-try drubbing.

Harbour have also never experienced victory on Lancaster Park-Jade Stadium since joining the old NPC first division in 1988, although they went perilously close on their last visit -- drawing 43-all in 2004.

Last year's match at North Harbour Stadium was a 23-all stalemate, indicating there has been little between the sides over the last two seasons.

Pollock joked a third draw -- which would see the shield remain in Canterbury -- was not an option.

"We're going paper, scissors, rock for it -- they've agreed to it -- we can't go three draws in a row."

Although sharing the spoils would enhance Harbour's claims to home advantage in the quarterfinals, the Air New Zealand Cup calculations took something of a backseat this week.

"These are opportunities that don't come around very often," Pollock said of the shield challenge.

"When we knew we had a challenge (after the top six draw was finalised), the team were all texting each other. It got round the group very quickly. It's an exciting opportunity."

North Harbour have made 10 previous bids for the Log o' Wood, initially against cross-harbour rivals Auckland in 1986 -- a year after the new union was formed.

Harbour failed in three more attempts to prise the trophy from Auckland's grasp but are perhaps best known for three unsuccessful challenges inside six weeks during 1996.

First up was Taranaki, who backed up their shock shield win over Henry's Auckland at Eden Park, by edging out Harbour 13-11 a week later.

Two weeks later the shield had moved on to Hamilton by the time Harbour arrived in town for their NPC date with Waikato, but the visitors headed back up the motorway empty handed after a 14-17 defeat.

Waikato subsequently lost the trophy back to Auckland, which completed Harbour's shield merry-go-round, with a 69-27 romp at Eden Park.

Pollock and Canterbury counterpart Rob Penney name their sides on Friday.

Canterbury will be without Richie McCaw's understudy Johnny Leo'o who suffered a leg injury during the 24-26 loss to Wellington on Sunday.

NZPA