Luke McAlister is undaunted by the challenge of stepping into New Zealand hero Dan Carter's boots for the final Test against the British and Irish Lions on Saturday.

The uncapped North Harbour utility back is a late replacement for Canterbury's Leon MacDonald who was due to take over the reins from Carter after his match-winning 33-point haul in the second Test in Wellington last Saturday. A groin injury picked up on Wednesday by MacDonald has forced the All Blacks into a rethink.

Carter was forced out of the reckoning earlier this week when the shoulder injury he picked up in the dying stages at Westpac Stadium failed to respond to treatment.

All Blacks coach Graham Henry raised a few eyebrows when he handed MacDonald the number 10 shirt as the home side attempt to secure only the third 'black-wash' in Lions history. The other two were in 1966 and 1983.

But his plans were thrown into disarray when a niggling groin injury forced the Canterbury man to pull out.

Chiefs backrower Sione Lauaki is also a late addition to the starting XV after openside flanker Richie McCaw had to withdraw due to a hamstring pull. Rodney So'oialo will move into McCaw's position with Waikato's Marty Holah added to the bench.

Henry has no qualms in giving the rookie 21-year-old McAlister his international debut, even though he brought Otago's Nic Evans into the squad as cover for MacDonald. With McAlister jumping the queue, Evans has been deposited on to the replacements bench.

"Luke will navigate the ship as best he can," explained Henry.

"He's going to have a lot of support.

"He's got Tana Umaga there alongside and Byron Kelleher inside.

"The game plan is pretty simple anyway, and we certainly don't have to simplify it any further. I think Luke will do okay, obviously. There are still a couple of days to work on combinations."

McAlister has played most of his recent rugby at inside centre - he played for the New Zealand Maori against the Lions in there - and concedes he has not "a hell of a lot" of experience in the crucial fly-half role but he remains unfazed with the challenge ahead.

"It's just one step closer in, that's all," he said.

"I'm sure the boys will look after me. There is a lot of experience in the All Blacks and I've been with them all week. So it's not as if I don't know them at all."

The versatile McAlister, whose father Charlie coached the Manawatu side earlier in the Lions tour, has experience of playing at fly-half as well as both centre positions for his province North Harbour.

At 5ft 10in and 14st, he is a more robust style of player when compared to Carter. He possesses a huge defensive game and is a prolific points scorer with his right boot.

He first burst onto the scene in 2002 when he scored 99 points for New Zealand Schools and 89 points in his debut NPC season with Harbour. He was selected for the All Blacks' end-of-season tour of Wales and France last season, but a hamstring injury ensured he was the only player in a squad of 32 who did not get any game time.

"It was frustrating to miss out last year," he said. "But I now have a chance to make up for lost time.

"It's unfortunate that both Dan and Leon have got injured, but I'm looking forward to facing the Lions."

Teams

New Zealand: M Muliaina (Auckland Blues); R Gear (Canterbury Crusaders), C Smith (Wellington Hurricanes), T Umaga (Wellington Hurricanes, capt), S Sivivatu (Waikato Chiefs); L McAlister (Auckland Blues), B Kelleher (Waikato Chiefs); T Woodcock (Auckland Blues), K Mealamu (Auckland Blues), G Somerville (Canterbury Crusaders), C Jack (Canterbury Crusaders), A Williams (Auckland Blues), J Collins (Wellington Hurricanes), R So'oialo (Wellington Hurricanes), S Lauaki (Waikato Chiefs).

Replacements: D Witcombe (Auckland Blues), C Johnstone (Canterbury Crusaders), J Ryan (Otago Highlanders), M Holah (Waikato Chiefs), J Marshall (Canterbury Crusaders), N Evans (Otago Highlanders), D Howlett (Auckland Blues).

Lions: G Murphy (Leicester and Ireland); M Cueto (Sale Sharks and England), W Greenwood (Harlequins and England), G Thomas (Toulouse and Wales, capt), J Lewsey (Wasps and England); S Jones (Clermont Auvergne and Wales), D Peel (Llanelli Scarlets and Wales); G Jenkins (Cardiff Blues and Wales), S Thompson (Northampton and England), J White (Leicester and England), D O'Callaghan (Munster and Ireland), P O'Connell (Munster and Ireland), S Easterby (Llanelli Scarlets and Ireland), L Moody (Leicester and England), R Jones (Neath-Swansea Ospreys and Wales).

Replacements: S Byrne (Leinster and Ireland), G Rowntree (Leicester and England), M Corry (Leicester and England), M Williams (Cardiff Blues and Wales), M Dawson (Wasps and England), R O'Gara (Munster and Ireland), S Horgan (Leinster and Ireland).

Referee: Jonathan Kaplan (South Africa).

Touch judges: Stuart Dickinson (Australia) and Mark Lawrence (South Africa).