British and Irish Lions 2017: Jonny Sexton talks up Owen Farrell relationship as he plots downfall of New Zealand

The duo have only played together twice on tour so far and looked far from impressive together in the first Test

Jonny Sexton and Owen Farrell have been burdened with the task of keeping the 2017 British and Irish Lions tour alive, no matter how unfair that may seem, after Warren Gatland named the two fly-halves as his orchestrators for what he hopes will be the All Blacks’ downfall in the second Test.

Gatland has decided to drop centre Ben Te’o, who offers defensive reliability and attacking directness, in favour of linking Sexton and Farrell together..

The Lions must beat New Zealand if they are to have any chance of winning the series in next weekend’s third Test, and Gatland has gone with what was widely considered as his strongest midfield pairing before the tour began.

Having got the tour off to a nervous start, Sexton found his form in the win over the Crusaders and the dismantling of the Maori All Blacks, although he did struggle when coming on during the first Test after shunting Farrell out to inside centre.

“I’m really excited about playing with Farrell,” Sexton said on the eve of the must-win second Test. “I’ve always admired him. We’ve got on great and stayed in contact since the last tour. We’ve got a good relationship – apart from trying to kill each other at the Aviva last time. We get on great.”

“I was asked whether it was the biggest challenge of my career to try to get ahead of Owen and because of the respect I have for him I said yes. He’s a world-class out-half. But I back myself and hopefully I can bring something to the team this week that will get us over the line.

“I’ve a big respect for him and we have a good relationship so hopefully we can click and make the team play better on Saturday and level the series.”

But with the Sexton-Farrell attacking line comes a defensive fragility that the selection of Te’o does not carry. Te’o gave Sonny Bill Williams a going-over last weekend, limiting the human wrecking ball to one notable offload over the course of the 57 minutes that the England centre was on the field.

The weather must also be factored into the equation. ‘Windy’ Wellington as it is known in these parts is due to receive nearly 24 hours of rain in the build-up to the second Test, which would appear to favour stick-it-up-your-jumper rugby and not the expansive game that the selection of Sexton and Farrell would suggest.

However, Gatland may well be deploying Plan B. The fact that Sexton is in the side obviously brings its defensive worries. That’s why Sean O’Brien will be tasked with defending between Sexton and Farrell, ensuring that the second hit on Williams comes from a 17-stone back-row rather than a 15-stone fly-half, with the result hoped to be the prevention of his trademark offload.

Farrell and Sexton have only been paired together twice this tour and never from the start (Getty)

Then there’s the matter of what the hosts want to do going forwards. Without Ben Smith at full-back, the All Blacks have been forced into a reshuffle due to the Highlander’s concussion issues. Israel Dagg has moved to the No 15 jersey, with Waisake Naholo starting on the right wing. With Farrell and Sexton both in the starting line-up, you can expect them to bombard Naholo and, to a degree, Dagg, to test the New Zealander's nerve in the wet conditions.

Three years ago, England targeted Dagg with the high ball and he crumbled under pressure. It may have been his first game back from a serious injury, but it would be a performance that led to his exile from the starting line-up for the next two years and, if it happens again in Wellington on Saturday, this will no doubt bring haunting memories flooding back.

Naholo is another consideration. The Lions saw first-hand what he can do with the ball, with the powerful wing blasting his way through Courtney Lawes en route to scoring against the tourists for the Highlanders two-and-a-half weeks ago. However, he is vulnerable, not least when receiving possession. Naholo does not cope well under the high ball given that he plays his club rugby beneath the roof of the Forsyth Barr Stadium, a dry arena that allows his best talents to take centre stage. Thrown into the difficult conditions of the New Zealand capital, Naholo is more likely to crack, and given he has the worst turnover rate of any of the All Blacks’ back line at one every 33 minutes, the Lions may be able to find an edge by putting him under pressure.

It’s no doubt going to be a huge challenge for the Lions. They have never come back from losing the first Test against the All Blacks to beat them in a Test series, and Sexton knows exactly how much it will take.

“It’s a huge challenge but it’s a huge opportunity," he said. "You don’t get many opportunities to create history, and to turn around a series like this after being 1-0 down would go down as one of the greatest Lions performances, so we need to view it as an opportunity rather than as a daunting challenge. That is the view we are taking. We have got to go and attack them and give it our best and see where that takes us.”

However, on Saturday it must only take them one place. Otherwise, like 2005 all over again, the series is done.