Celtic Rangers Old Firm clash will be whole new ball game for Brendan Rodgers
Regardless of whatever half of the divide you come from, Alex McLeish knows exactly how Brendan Rodgers will be feeling in those private, nerve-shredding moments before settling into his first experience of the famous Old Firm derby.
Rodgers has always been one of those unruffled, considered coaches: a contemporary thinker of the game, less prone than most to bouts of erratic behaviour.
The unique, swirling cesspool of the Glasgow clash can shake even the most measured of men. And with Rangers arriving at Parkhead on Saturday for the first time on league business in over four years, Carnlough native Rodgers needs, somehow, to keep his cool.
The Hoops manager has guided his new charges to the lucrative Champions League group stages - with an estimated £30m pocketed as a result.
Nevertheless Rangers, under Mark Warburton - Rodgers' old friend from their days at Watford - is a different, familiar, challenge altogether. As ever, pride and reputations matter with the Ibrox side gradually settling into SPFL life.
Celtic have been in fine form with three successive wins to open their domestic campaign.
Big Eck knows from experience that Ulsterman Rodgers will be excited, where the outcome of an Old Firm game is capable of setting the tone for a managerial career.
Speaking to the Belfast Telegraph, he said: "Everyone told me when I took over at Rangers that nothing will ever prepare you for the emotions you feel at the start of an Old Firm derby. It is all about personal feeling and everyone is different.
"Brendan, though, has the character and experience in his coaching career so far to absorb things. He will know that in football you can't always have it good and everyone at one time gets a bad feeling about certain games and situations. You're only human.
"He is a good guy and has a cool, collected temperament which does help in this particular game. But he will find it's definitely unlike anything else.
"I know Brendan from when I was at Birmingham City. He came to visit us to have a look at training for a couple of days when he was out of work for a few ideas."
Rodgers also has to cope with the demands at Celtic, with the Hoops targeting victory in the notoriously unpredictable encounter.
"Celtic are favourites but you really never can predict the outcome," added former Scotland boss McLeish.
"I remember Old Firm games when you had high hopes but ended up getting a tanking. But I feel Celtic have fresher legs and better pace. Rangers had a lot of pace last year but that was in a lower division."
Rangers need to show steel at Parkhead if they are to gain something, according to their ex-manager, who guided the Light Blues to seven trophies between 2001-2006, including two SPL titles.
"They have added older players who are maybe slightly past their peak, like Joey Barton who is 33 and Niko Kranjcar," notes McLeish. "Will they get that required level of fitness?
"There has been a lot of talk about Joey playing against Scott Brown and the possibility of a red card or two being thrown in which no doubt the press would love to see. Joey still has potentially another few years of good football left, a bit like Gordon Strachan when he was at Leeds.
"Mark needs his main experienced guys like Joey, Kranjcar more than ever on Saturday. He needs them to take on the occasion, help the younger players and perform.
"Believe me, Mark needs these guys. The biggest factor for both Mark and Brendan is that you need to win every game - so no pressure there!"
McLeish misses this old showdown. And he advises everyone to grab the occasion.
He recalled: "My first Old Firm game at Celtic Park when we drew, I was with the team on the bus doing the team talk and I remember all the backroom staff exhaling their breath when they saw the 'welcome' the Celtic fans gave us.
"I said to the players and staff 'take it all in - these are the greatest days of your life. Think of all the people who never get to experience this'. We were getting dug at by the Celtic fans but I had a team of big egos and top characters like Ronald de Boer, Lorenzo Amoruso and Arthur Numan who lapped it all up.
"It's very important to put a marker down on Saturday, which is what Brendan will obviously want to do. When you win it gives you so much confidence. Rangers winning the Scottish Cup semi-final last season against Celtic was very important to Mark but this will be different.
"More than anything, both managers need their players to keep their composure no matter what. I'm looking forward to this game more than any Old Firm game in a long time."
Rodgers and Warburton were first team and academy managers respectively at Watford previously, but McLeish knows from his own experience the old friendships are parked for the duration of residence in Glasgow.
"Friendships definitely don't redevelop," he insisted.
"I go way back with Gordon Strachan (at Aberdeen) and when he took over at Celtic he told me that we need to have a night out with the girls. All the time I was thinking 'no chance'. And when Gordon left Celtic, he said to me: "We never could get that night out could we?
"It's a privacy thing, really, and although Brendan and Mark are friendly you have to keep a distance, but there will always be that respect.
"I had it with Martin O'Neill when he was at Celtic. Obviously you couldn't say too much to each other after games, but you would joke that such-and-such a player was a real scourge, that type of thing.
"You have respect for each other because you know what it's like to walk in each others' shoes. There's no spare time anyway to even catch your breath when you are in charge of Rangers or Celtic."