Wigan Athletic set to look to Manchester United's Ryan Giggs
Mackay is the subject of an on-going FA inquiry into allegations that he sent homophobic, racist and sexist messages while in charge of Cardiff.
And his contract at the DW Stadium contains clauses ‘protecting’ the club if he is eventually charged.
Should Whelan be forced to part company with his new Latics manager when the FA delivers its verdict, then he will be on the lookout for a replacement.
Sunday People Sport understands Manchester United legend Giggs is under consideration with former team-mate Nicky Butt as his No.2. Giggs is currently assistant to Louis van Gaal after being in temporary charge at Old Trafford after David Moyes was sacked last season.