By Phil Gordos

Great Britain kick off their Gillette Tri-Nations Series campaign against defending champions New Zealand in Christchurch on Saturday.

The Lions made a poor start to last year's tournament and eventually missed out on a place in the final.

They will be hoping to get out of the blocks a little quicker against a Kiwis side who have lost their first two games to Australia.

But where will the match be one and lost? BBC Sport picks out three confrontations that could prove crucial.

Stacey Jones dominated last year's Tri-Nations Series, kicking and cajoling his side to a shock success.

Stacey Jones and Sean Long

Still only 30 and despite numerous international retirements, the 'Little General' remains an influential player for the Kiwis.

If the 2002 Golden Boot winner is given room to manoeuvre, Britain will spend most of the game on the back foot.

The Catalans Dragons scrum-half can split defences wide open with his kicking game and put opponents under pressure with his defensive clearances, too.

Sean Long has admitted he has so far failed to deliver on the international stage, but there is no doubting his ability.

The 30-year-old scrum-half's kicking game is key, but it can be both his strength and weakness.

When he is on song, he can unpick any defence with a well-placed grubber kick, a little chip into the corner or a high boot into the in-goal area.

But his defensive work sometimes comes up short.

Long, who scored two tries and kicked 12 points as the Lions crushed New Zealand 46-16 in June, will go into the game full of confidence after winning honours galore in 2006.

Ruben Wiki is another pivotal figure for the Kiwis. He leads from the front and is one of the biggest hitters in the game, both going forward and in defence.

Ruben Wiki and Stuart Fielden

The prop, who can also play at second row, broke Gary Freeman's record of 46 caps last year.

At 33, his international career may be drawing to an end, but the New Zealand Warriors forward has lost none of his thirst for battle and will be keen to show the likes of Stuart Fielden that he is not a fading force.

Stuart Fielden is widely regarded as one of the best forwards in the world - and the most feared.

He is also one of the main players Britain look to provide inspiration on the field of play following Andy Farrell's defection to rugby union and the absence of Paul Sculthorpe because of injury.

After an enforced rest following Wigan's failure to make the Super League play-offs, Fielden will be more fired up than ever to show the might of the southern hemisphere that he is still a force to be reckoned with.

If the former Bradford Bulls star can get some steam up, expect him to bash big holes in the New Zealand defence.

Manu Vatuvei has already been dubbed the Jonah Lomu of rugby league.

Manu Vatuvei and Brian Carney

The winger is also known as 'The Beast' and was dubbed 'a monster' by New Zealand Warriors team-mate Steve Price, a former Australia international.

Aged 20, Vatuvei stands 6ft 2in tall, weighs in at 17st 2lb and takes some stopping once he gets up to top speed, which does not take much time at all.

He gave both Britain and Australia nightmares in last year's tournament, more than making up for the absence of fellow winger Lesley Vainikolo.

Vatuvei went on to score two tries in the shock 24-0 success over the Kangaroos in the final, but he has only registered one score in two matches so far this year.

That may change if he gets good service on Saturday and the Lions cannot get to grips with his imposing frame.

Brian Carney made a disastrous start to last year's competition, dropping several high balls and coming off second best to Vatuvei in the 42-26 loss to New Zealand in London.

The Irishman, who was vice-captain in 2005, was vilified by the media as a result but showed his strength of character by bouncing back from that humiliating night at Loftus Road.

Now playing his rugby in the NRL, the 30-year-old winger was the top tryscorer for Newcastle last season with 16 and will be accustomed to conditions in the southern hemisphere.

The former Wigan star should also be a better player.

Always a threat in attack, his defence should be a lot tighter after coming up the likes of Vatuvei every week in the NRL.