Wallabies jump-start their campaign but Lions can restore pride

"I have no doubt that Australian can [win the series next week]," the Scot said.

"The Lions know they have to improve and in Melbourne the Wallabies proved that if the right things are in place, then the momentum of it soon changes.

"Australia lost badly to France in the autumn last year but then they dogged out wins against England and Wales.

"Wallabies players have said they're staring down the biggest game of their careers in Sydney and that's what the Lions bring to the table.

"But it's also what the Lions have to understand. Their opponents see the third Test as the biggest game they've ever played outside a World Cup final and that's the challenge – you don't play opposition who have that mindset in every international game."

McGeechan, who captained Scotland nine times while winning his total of 32 caps, played in the Lions "invincibles" tour of South Africa in 1974.

"The trip changed me; playing next to and getting respect from great players like Gareth Edwards and JPR Williams gave me a different perception of what I, or indeed what any team, could achieve," McGeechan added.

As well as leading Wasps to Heineken Cup and Aviva Premiership titles, McGeechan coached the British & Irish Lions five times, leading the 1989 side to a 2-1 series win on Australian soil.

He is now hoping that history will repeat itself on Saturday in a match Australian supporters consider every bit as important as the 2003 World Cup final staged at the same venue.

"Probably psychologically, I think Australia would have got a lot out of beating the Lions in Melbourne by scoring the only try of the game," McGeechan said. "In the first Test match in Brisbane, the Lions would have been disappointed not to kick on and maintain control with the fresh props on. They definitely lost that control, so that is something they will have to work hard at putting right. Australia scrummaged well and their substitutions were far more effective in the game and that's another area the Lions can improve but it won't be easy.

"The Wallabies are comfortable at grinding out wins. In the third Bledisloe Test in Brisbane last year, they came back from a 22-0 loss in the second Test to draw 18-18. That takes some doing against a side like New Zealand. That is what the Lions have to respect, that Australia know how to find a way back, and generally do."

Despite awarding Australia his "favourites" tag for the third Test, McGeechan believes Warren Gatland's men have yet to play their best rugby.

Eighty minutes now stand between the Lions writing a new chapter in their glorious history, but McGeechan says they must not make the same unforced errors that have affected how the Tests thus far have panned out.

"The Lions will be a little bit disappointed with some aspects of their performances in the first two," he said.

"They have to be impressed with Australia's passing and running, and the speed, but I do think the Lions believe there is a type of rugby in there that they know, if they can produce it, will be very difficult to stop.

"They know that if they get their game right, it is going to be tough for Australia. But whoever wins, it's going to be very close in Sydney."

McGeechan believes the biggest advantage for the Lions is a fear of yet another series failure in Australia's back yard, having been just minutes away from winning the series in Melbourne.

"There was huge disappointment for the Lions in South Africa in 2009," he recalled. "We played great Test-match rugby but lost the second Test – and therefore the series – in an injury-time kick. We got it right in the third Test [the Lions beat the Springboks 28-9] but everyone remembers losing 28-25 in Pretoria.

"All of the 2013 coaching team bar one [Andy Farrell] were there in 2009 with me and they still remember it. That is driving them this time, that attitude of 'we're not going to let it happen again'."