Whether Mackay will continue to be the one making such decisions remains to be seen. But he has been sure to leave an imprint on his first outing as interim manager by handing debuts to Christie and Rangers midfielder Ryan Jack, who starts at right-back.
Scott Brown has been ruled out, although Mackay directed questions about the specific nature of his injury to his club, Celtic. Club team-mates Craig Gordon and Kieran Tierney are, however, set to start, the latter at left centre-half.
Mackay confirmed winger Matt Phillips will take his place in the side as a striker, having been assigned the role at the beginning of the week in preference to Jason Cummings.
McLean, meanwhile, wins only his second cap and, with the rest of the Aberdeen contingent – Graeme Shinnie is also in the squad – will aim to make Kris Boyd look foolish after he scoffed at their inclusion.
The Kilmarnock striker described the pandering to Aberdeen fans as “a laughing stock” in an interview with Radio Scotland’s Sportsound programme on Tuesday night. He maintained McLean, Christie and Shinnie were included only to boost the crowd, with the tickets sales standing at around 15,500 as of last night.
In a surprisingly frank outburst at fellow professionals, Boyd also described Jack as having had “more red cards than good games for Rangers this season”.
Mackay revealed he had not felt the need to speak to any of those targeted by Boyd.
He said: “It’s not about proving anybody wrong.
“These are professional footballers. They go out every week. For that they deserve respect, they deserve that little bit of respect.
“They don’t go out to prove people wrong. They go out to prove themselves right, to show they deserve to be a footballer. They go out to make sure they impress their manager, their family to an extent and in this case me and my staff. It is not about proving people wrong it is about proving themselves right, about showing they deserve to be out there.”
“Players get criticised every week. Media, social media, whatever it may be,” he added. “It’s part of the whole thing.
“The players who trained this week have been terrific, with some guys coming back to their home city. How good is that?
“So, absolutely not, I don’t see them being affected. It’s water off a duck’s back. I’ve not felt the need to speak to them. It’s part of the whole thing.”
Mackay also dismissed the suggestion Christie and McLean will feature in the starting XI because of the need to sell tickets. “Trust me, that’s not something that was an issue,” he said. “Honestly, there’s no way that was the case. Look at the squad. It is players who are playing at a good level.”
Jack has not only had to face Boyd’s withering remarks but could also be targeted by Aberdeen supporters still upset at the manner of the former Pittodrie skipper’s exit to Rangers at the end of last season. The Aberdonian could have to endure the surreal experience of being jeered on the return to his hometown to make his international debut.
Mackay said: “Footballers have to deal with everything.
“He is not the first player to go back to his hometown. What I would say is that it is Scotland that’s here tomorrow night and not Aberdeen – there will be a lot of Aberdeen fans here, but it is Scotland that’s here. And I would love Scotland fans to cheer Scotland players tomorrow night.”