The duo made their European debuts for the Dons in Thursday night’s 1-1 draw against Siroki Brijeg which means they’ve already started as many matches together for the Pittodrie club as they did during their time together at Parkhead.
That solitary occasion under Brendan Rodgers came in a 2-1 home win against Dundee last December, shortly before Christie departed for a first successful loan spell with Aberdeen.
Now he is back for the season as part of the deal that took Jonny Hayes in the opposite direction, but the fact the Celtic manager blocked Derek McInnes’ attempts to make it a permanent switch means he might eventually have a future with the champions after all.
Not so Mackay-Steven who was sold for £150,000 earlier this week after the player signed by Ronny Deila started just five games for the current Celtic manager, a frustration Christie can certainly empathise with.
The pacey winger does have one advantage over Christie in that he is eligible to play when last season’s top two teams meet in the months ahead but the midfielder admits they are just grateful for the chance to play regular first-team football with Aberdeen.
“I was chuffed to hear that he’d managed to sort a deal out,” said Christie. “He’s a great player and one I’m definitely looking forward to playing with.
“He’s so positive with the ball at his feet, a player that takes defenders on in the final third and looks for that killer pass.
“For Gary it’s good he’s come somewhere that, hopefully, he’ll get to play some football again. It was difficult, but it’s not just Gary’s position, it’s the same across the park at Celtic. Especially last season, the guys who were starting were going into every game and producing so it’s incredibly difficult to break into the team.
“Hopefully this season he can kick right on and get back to the kind of form he was in and he mentioned that the difference between me and him is that he’ll be able to play in the big games against Celtic.
“Obviously I’m a bit frustrated to have to sit those out this season again,” said someone who avoided a conflict of interest in last season’s Scottish Cup final between the pair by watching it on television while on holiday in Florida.
The reunion with Mackay-Steven is not the only example of friends reunited for Christie, though, as his former Caley Thistle team-mate Greg Tansey is also an Aberdeen player now.
They, along with the new Dons captain Graeme Shinnie, were key factors in helping Inverness win the Scottish Cup and qualify for Europe for the first time two years ago.
Now the aim is to steer the Dons closer to the Europa League group stage by eliminating Siroki Brijeg in Bosnia on Thursday with the incentive of a surely winnable third-round tie, probably against Cypriot side Apollon who lead 3-0 from the first leg against Zaria of Moldova.
That would mean a rapid return to Cyprus for Kari Arnason who rejoined Aberdeen on Friday after being released by Omonia Nicosia, as the Iceland international will be clear to play if Aberdeen progress.
Christie believes Tansey will have a key role to play in that when they travel to the 7,000 capacity Pecara Stadium as the hope is his former Caley Thistle colleague can prove Ryan Jack’s recent move to Rangers will prove no big loss.
He added: “Greg was always a great player at Inverness, always performing, producing week-in, week-out, so it’s only right he has made the step up.
“Greg will go under the radar a bit but on Thursday night he showed his range of passing, When you’ve got so many attacking bodies in the team, you need someone to just sit in behind and that’s something he can definitely do. I think it will probably be his main role to protect our back four and he’ll only get better as we gel as a unit.”