Although the Scot is expected to be named as the successor to Tony Pulis, who left the club last week, the only confirmed news coming out of the club was that caretaker boss Keith Millen would take care of pre-match media duties on Thursday
Betting was suspended by many bookmakers on the prospect of former Cardiff boss Mackay being appointed, and an announcement may still come before Saturday's London derby at home to West Ham.
With Palace chairman Steve Parish insisting he wanted a quick appointment, Mackay, 42, appears to have beaten former Tottenham manager Tim Sherwood to the position.
The Palace press office confirmed in a routine media release that Millen is due to speak with the media at Selhurst Park ahead of the West Ham game.
Millen could take charge of the side against the Hammers, even if the permanent replacement is named.
The 47-year-old oversaw a narrow 2-1 defeat at Arsenal in Palace's Barclays Premier League opener - a fixture which came less than 48 hours after Pulis departed by mutual consent following a breakdown in his relationship with Parish
He took charge in November with Palace the heavy favourites to fall out of the division, and led the Eagles on an inspired run which saw them finish 11th and remain in the Premier League for more than a solitary season for the first time
If appointed, Mackay could look to add to the summer signings of Chris Kettings, Fraizer Campbell, Brede Hangeland and Martin Kelly.
Mackay would also again link up with Palace's sporting director Iain Moody, reuniting the pair following stints together at Watford and Cardiff.
Source : PA
Source: PA