"Ian's second to none as far as a Lions coach is concerned," said Irvine, who was capped six times by the Lions on the historic 1971 and '74 tours and then toured South Africa for a second time in 1980.
"I've known Ian for many years. We were first capped on the same day together and we went on to play many times for Scotland and the Lions together. I obviously know him well and so does (Lions tour manager) Gerald Davies .
"The great thing is that it wasn't just that Ian was available - he was very keen to do it. That says a lot about the chap. When you've been coaching for so many years, sometimes you can lose a little bit of interest and your desire can fade, but not in his case. He's probably as excited about this tour as any, and I think that's a great thing."
McGeechan led the Lions to a stunning series win over the world champion Boks the last time they visited South Africa and Irvine has every confidence that his old friend has what it takes to achieve a similar feat this time around.
"Ian was out in South Africa in 1997 with the Lions and he knows how important it is to blend the players together to get a feeling of unity.
"I think Gerald is very much from that old guard as well. That's very much the way I think towards the game so there's a common view there. I'm very confident that they will get it absolutely right out there."
Lions chairman Andy Irvine and a giant version of the new adidas Lions shirt
Having lost to the Wallabies in 2001 and the All Blacks in 2005, Irvine admits that the most-recent series victory will play an important part in the Lions' planning for next year's tour. The Lions were huge under dogs when they arrived in the republic 11 years ago on the first professional tour but McGeechan somehow ensured his men came home with an impressive win. Irvine is keen for the same result next summer and he feels McGeechan's experiences in '97 could swing the series in the Lions favour.
"The 1997 tour will have a big influence. If you look at the record over there, we were not favourites.
"We sprung a few surprises, particularly in selection for the first Test, and that was master minded by Ian McGeechan and Jim Telfer.
"That's one of the reasons why Ian is coach this time because he's such a great strategist. He also knows South Africa inside out. Having won down there in 1997 will be a confidence boost for the players.
"It's going to be a fantastically-exciting tour and we've got a lot to make up for. Having been whitewashed in New Zealand, it's very important to put the Lions on the map in a winning way."
The new adidas Lions shirt is available in the shops from December 11. To avoid the rush, why not pre-order your shirt by calling the adidas customer careline on 0870 240 4204.