The vindication of his decision to choose the Gorgie club rather than explore the possibility of joining rivals Hibs, will not come after just one 90 minutes, but a win over the Leith side on Sunday would be a step in the right direction.
While Jack Ross tackles the first derby of the season with a squad he states is still one attacking player shy of where he wanted it to be, his Tynecastle counterpart Robbie Neilson says he will give his latest recruit game time in the table-topping tussle.
That opens the 26-year-old Scot up to scrutiny as home fans hope for a performance that will leave their rivals gutted by what might have been and the away throngs wait, poised and ready to gloat should he deliver the kind of underwhelming start that would permit them to promptly declare him someone Hearts are welcome to.
“There would be a spotlight on me anyway because I am coming back up the road and I’m a new signing,” said the former Rangers winger. “But the derby game will take care of itself and I just have to play my own game if I’m involved and get any time on the pitch. I can’t let it affect me.
“I had other offers up here, down south, and abroad. It was a case of picking somewhere I knew I could settle and just get back to playing football and enjoying it. I know quite a lot of the boys here and they said it was a great set up, with a great bunch of lads.
“It's important when you go into a changing-room that everyone is pulling in the right direction.
“I've never been to [an Edinburgh derby] but I've watched them. You know the hostility you get, the feisty tackles, all that stuff. Every derby is the same. Edinburgh derbies have that little edge. I've always watched them when they have been on.”
Recently the man in the middle as the two capital foes competed, McKay would love to think that Hearts’ doggedness in winning that battle will be reflected on the field.
A long-time suitor, Neilson was eyeing up possibilities even when McKay was at Rangers. He monitored him during his loan spell at Fleetwood last season and made an approach when he exited Swansea City in the summer. But it has taken months of perseverance to get their man.
And, that tenacity, impressed McKay.
"It's been a long time coming. But, persistence pays off! The project, facilities and squad they've got here are great and they want to do something really good this year.”
And after experiencing Tynecastle as a visiting player, he is happy to be making himself at home there.
"When you’re in the opposition team it's tough. I'm looking forward to fans being behind me this time. I haven't played in front of fans for 18 months so it will be special to have them back in.
"No matter your fitness levels, adrenaline gets you through a derby. I've trained all week and I feel good so hopefully I can be a part of it.”