"There wasn't a strong foundation on which to build that relationship. When I was playing with Stephen Jones, we were almost trying to build a foundation and decorate our bedroom at the same time. It was a really challenging experience.
"Looking at this tour, it seems as though that foundation has been laid. Yes, they've lost a few games and drawn one, but even the losses have hammered the foundation down.
"In defence, with the forwards and everything, there is a real dependence there, something you can count on. When you add two decision-makers on a strong foundation, you can start to build quickly and cleverly."
At least Sexton and Farrell, two veterans of the Lions' 2013 series victory against Australia, have accrued game time together in New Zealand, playing in the 12-3 triumph against the Crusaders and during the final quarter of last Saturday's 30-15 loss to the All Blacks at Eden Park.
There will be plenty of sceptics who see their selection for Saturday's Test as a death knell for the Lions, but Wilkinson is not among them. This is a man who knows what it takes to succeed at 10 and, having worked alongside Farrell as a consultant coach in Eddie Jones's England set-up, he suggests these two tenacious characters could drive the Lions.
"You have to be ruthless as a 10," Wilkinson says. "You have to go to depths of thinking that go beyond 'What do I want?' - it's a can of worms, but you have to go there. You've already opened it by choosing to play 10. That brings a strength in conviction which people love seeing in and around them. You look to your left and you see someone speaking with such assurance.
"Once [Sexton and Farrell] have the foundation there, they can take the number off their back. They can be a player as well, taking the ball to the line, making offloads, putting guys through holes, kicking the ball over the posts or putting it in the corner.
"That's where the real ability is. It's not saying: 'I'm a 10, this is what I do'. It's saying: 'That is part of my game, which is massive benefit to the team, but I can take my number off and I'm still out here'. You don't take the number off and wither. When you have that balance, when you're both in the game and controlling it, it's an amazing feeling.
"Having another guy out there means they'll be able to say: 'Go and have your crazy five minutes while I look after stuff. Because when I have mine I want you looking after me'. That's what the difference was for me."
Some of Wilkinson's fondest memories from his own playing career flow from his games in harness with Mike Catt in England colours and alongside Matt Giteau at Toulon, and he does not rule out the possibility of sparks between Sexton and Farrell.
"When Mike or Matt were taking the ball at first-receiver, I would have time to sit back and look and go: 'Hold on, what can I see?' Instead of needing to be at first-receiver all the time, you can see something - 'If we do that three times, bang, we'll score'.
"A lot of 10s try to organise so much that they forget to spend time on their own attack, their own passing and footwork. [Sexton and Farrell] seem to always be spending time working on the individual stuff as well, and when you set them together they might just be an inspiration to each other."
Wilkinson cites 2005 rival Tana Umaga as evidence of New Zealand's tendency to produce powerful centres who do not compromise on playmaking ability, as opposed to northern hemisphere nations that often have to "make a decision" between guile and heft in midfield.
Gatland's omission of Ben Te'o deprives the Lions of a gain-line presence that stifled the influence of opposite number Sonny Bill Williams, another of Wilkinson's ex-Toulon team-mates, at Eden Park.
Wilkinson remembers Williams causing havoc in France - both as an offloader and a decoy runner who consistently attracted "two or three" defenders. With the Lions intent on saving the series in Wellington, Gatland has gambled.
"If you start thinking 'I don't want to have Sonny Bill flying through there and throwing offloads', you start reacting," Wilkinson says. "In an ideal world, you are proactive. You picture how you see yourselves playing absolutely amazingly. What's the line-up like? You go for that.
"At the same time, when you are playing New Zealand, if you don't react to their strengths, you are going to find it very difficult. It's Gatland's challenge."
By Charlie Morgan of the London Daily Telegraph
