John Hughes and John Collins have enjoyed a number of tactical battles over the last few years.
Many were waged on Craigielaw golf course, although a few others took place in the cafeteria as the two men conscripted salt and pepper pots to play out imaginary tactical duels in front of local club members.
There is a similar exchange in store at noon tomorrow when Hughes' Inverness Caledonian Thistle side host Celtic, where Collins is now employed as assistant manager. The dimensions of the tactical areas will keep the two men apart in the Highlands, rather than the width of a canteen table.
Hughes joked yesterday that he is "far cleverer" tactically than his friend, despite the coaches holding similar beliefs about how they want teams to play. The Inverness manager will try to prove tomorrow that he also has the measure of Ronny Deila, the theories espoused by Hughes in between meals having at least taken his side to the top of the league table ahead of the visit of Celtic.
"I'm looking forward to locking horns with John Collins," said the Inverness manager. "He's a very good friend and someone I spend a lot of time with. We talk football - the lads at the golf think we're half-daft moving salt pots and pepper pots about while we're talking tactics. But it's all about football and you see the knowledge and passion John's got for the game.
"He is a very clever man so I'm delighted he's back in the game at that level. He deserves it. He's clued up and ahead of the game in a lot of respects. The way he sees the game and approaches things, with his lifestyle and fitness, is exemplary. If he's having a big input at Celtic they'll play in the right way."
Deila's dilemma may be whether to simply tinker with his team or make wholescale changes with the prestige and multi-million cash prize of the Champions League group stage at stake just a few days later. Celtic will contest the second leg of a play-off with Maribor next week.
"Celtic's biggest game of the season is next Tuesday in the second leg against Maribor," said Hughes. "So you do wonder what sort of team they'll put out against us. But look at their bench from the other night; they have guys like Nir Biton, Kris Commons and Leigh Griffiths.
"They're still recruiting as we speak so they could have a couple of new players in by then as well. It doesn't matter what team they put out, it will be formidable. Even their bench has international players on it - they have a very strong squad."