They don’t have the same blood bond as brothers Graeme and Andrew Shinnie.
But Dons skipper Ryan Jack and Hibs midfielder Fraser Fyvie are as close as any non-siblings could possibly be.
Born and bred Aberdonians, they began playing football together from the age of just seven.
Jack and Fyvie were almost joined at the hip as they rose through the ranks at Pittodrie to eventually appear together at first team level.
It’s why going head-to-head for the very first time in the Scottish Cup semi-final will mean just as much to them as it will to the Shinnies who will also be in rival camps at Hampden tomorrow lunchtime.
Former Dons boss Craig Brown managed both players during his time at Pittodrie.
He’s looking forward to what he feels could prove to be a decisive midfield duel between them at the national stadium.
“There will be no prisoners taken, that’s for sure,” said Brown, who will be at the game in his role as a Dons director.
“My hope was that Ryan and Fraser would eventually become the main midfield pairing for the Dons.
“Fraser moving to Wigan put an end to that but it’s good to see him back in Scotland doing so well for Hibs. He doesn’t need me to tell him Ryan won’t be thinking about their friendship in the semi-final.
“I’ve worked with many players over the years, but few have possessed the sheer will-to-win attitude Ryan has.
“He stands down for no one. I saw that when he spoke back strongly to Archie Knox (Brown’s assistant at Pittodrie) during a game.
“It takes a very brave man to do that!
“Ryan is as defiant on the pitch, too, and he won’t want to see Fraser getting the upper hand at Hampden.”
Fyvie helped Hibs win the cup last season and is desperate to see them retain the trophy, but he has never disguised his love for the Dons.
It’s all about helping Hibs come out on top tomorrow though, with the chance to finally face up to Jack an added bonus.
Fyvie said: “I played alongside Ryan since I was seven, and keep in touch with him regularly.
“There’s been a bit of banter about the cup match, as you would expect.
“I know Ryan will make it tough for us.
“He is the Aberdeen captain and that speaks for itself. Ryan has done fantastically well in the last few seasons and he is highly regarded in Scottish football. He is a fantastic player and one of the first names on the Aberdeen team-sheet.
“But it will be a simple case of ‘see you after the match’ this time. Hopefully, Hibs can come out winners on the day and get ourselves to another final.
“That is what we want to do, regardless of who is on the other side.”
Brown, as you would expect, is hoping for a Dons win.
Even more so because Hibs robbed him of the chance to lead Aberdeen to the Scottish Cup final in 2012. The Edinburgh side won 2-1, but in controversial circumstances.
Striker Gary O’Connor came back from an offside position to set up the winning goal for Leigh Griffiths, now of Celtic.
Brown said: “That was the biggest disappointment of my career as a manager.
“It’s why tomorrow’s game will be a bit of a revenge mission in my head. We were robbed, O’Connor was clearly offside.
“The SFA’s referee chief called me later to apologise.
“He said the ref’s assistant had lost concentration and failed to spot it. It was no consolation to us, though. Hopefully there will be no repeat of anything like that tomorrow and we get to enjoy an Aberdeen victory.”