Last month, Malkay was appointed as a replacement for Gordon Strachan on an interim basis, and it was expected that the former Cardiff City and Wigan Athletic manager would be considered for the role on a full-time basis.
However, ahead of Thursday's clash with the Netherlands, Regan has said that the governing body is only considering other names for the job.
Regan told talkSPORT: "No, Malky and I have discussed this. He's got a big job on his hands, he's said that himself.
"He's been asked by the board to take charge for one game and that's what he's doing. He's very proud to lead his country."
Mackay has not featured in the dugout since April 2015, when he was sacked as Wigan boss after winning just five of 25 games at the DW Stadium.