Mackay was West Ham captain under Pardew during his playing career, and was approached by the Magpies boss with a view to becoming his assistant at St James' Park.
But the Scot chose to remain at Watford, before joining Cardiff in the summer of 2011 and steering them into the Premier League two years later.
He said: "I could have been at Newcastle. We had that conversation concerning me going up there as his number two, but it didn't happen.
"I know Alan well, he is a good friend of mine and he has certainly been a mentor for me over the past few years in terms of conversations we have had.
"I also played for him, I was his captain at West Ham, and he is a good friend of mine and he has done a very good job at Newcastle. He was given a long-term contract and he has brought stability to that club to an extent.
"You look at the recruitment he has orchestrated there in his time and that stability is important in football, and that is what I am trying to do here in terms of staff and recruitment.
"The first half on Monday was probably not what he wanted and he probably had words at half-time, he changed things a little bit.
"But in the second half they played like the Newcastle I have seen over the years he has been there and they could have nicked a draw, which would have been unbelievable on the night.
"So I am expecting a tough game against a team who on their day can take anyone apart."
Mackay is keen to build on last weekend's 2-1 win at Fulham ahead of the international break.
He said: "It was great to get three points last week. It gives the players belief in their ability to pick up points on the road so it was a very good day.
"We want to collect points every week. Any game at home you want to win as you know all away games are tough, so you have to make sure you send your team out with the right attitude."