Huddersfield have appealed against the red card shown to Anthony Gerrard in last Saturday's draw with Crystal Palace.
The defender will now be available for the Terriers' Boxing Day clash with Blackpool.
Gerrard was sent off with around 10 minutes left at Selhurst Park following a challenge on Yannick Bolasie.
Town were incensed at referee Graham Scott's decision, who had dismissed Palace's Damien Delaney in the 11th minute.
The FA will review Gerrard's dismissal on Thursday, freeing the player up when Town play host to manager Simon Grayson's former club at the John Smith's Stadium.
McKay has been a revelation at Inverness since arriving on a free transfer from Northampton in the summer.
The 24-year-old netted his 17th and 18th goals of the season in Saturday's 4-1 SPL win over Dundee, to make it 12 goals in his last seven games.
McKay's performances have attracted interest from a number of clubs south of the border and Leicester and Forest are both thought to have watched the Northern Ireland international in action on Saturday.
Leicester and Forest are both thought to be in the market for striking reinforcements in January and they could test Inverness' resolve to hang onto their star striker.
