The 27-year old midfielder was the star man as Australia demolished Uzbekistan 6-0 in the Asian Cup semi-final on Wednesday morning, backing up solid performances against Bahrain and Iraq in matches prior.
Now Postecoglou feels that clubs overseas may start to come in with offers for the diminutive McKay, who has emerged as one of the premier midfielder in Australia's domestic competition in the last few years.
"Probably, why not? I'd sign him," the Roar coach said after last night's 2-0 win over Wellington Phoenix.
"That's a fact of life and the better we do, the more attention our players get and that's fine. I'm totally comfortable with that, but the key is that we keep investing in our football department."
Postecoglou said if the skipper did decide to part the club for foreign shores, the current league leaders would be able to remain as one of the forces in the A-League.
"If we do (lose him), I'm confident we can continue on the way we've started. Letting players move on is not such a negative thing. They're going onto bigger and better things and that's an acknowledgement of the work we're doing here," he added.