The two were together at Celtic and against each other in East Anglia earlier in their careers.
This season sees both men challenging with their sides in the top six of the Championship.
We were at Celtic together," said Mackay ahead of todays game. Tony was in the first team when I was coming through the reserves.
Then he moved to Ipswich Town and not long after I signed for Norwich City. We played against each other a few times and met up occasionally, quietly near the Suffolk/Norfolk border so that fans of each club didn’t see us.
"He has Middlesbrough well organised and playing the way he wants. It is Tony’s team and they are going to give us a real test."
Speaking to the press on Friday Mackay praised his squad and they way they play for each other. He acknowledged the need to strengthen.
“This is a young group coming together and there is huge room for improvement,” he said. “You will hear that from players, from myself and coaching staff. What I am delighted about is the way the players are throwing themselves into it and playing for each other.
“The squad has to improve in terms of the size and the depth. But it will be when the right person comes available not just a scattergun approach.
“The market is certainly inflated in terms of the prices, unless there’s someone coming out of contract. Inevitably in those cases everybody and their dog will know about it.
“Apart from Man City, I think everyone is financially restricted. We have budgets that we work to and we’ll work within them.”
Tony Mowbray also acknowledged his past with Mackay.
He explained: "Malky Mackay is a good friend of mine, I played with Malky at Celtic when I was a more experienced player and we played a lot of football together.
"I know him very well. He's a good man, an honest man, a very hard-working guy, I know his family well and I'm delighted he's achieved what he has achieved in his career, doing well with limited resources.
"Taking on a different challenge at Cardiff with different expectations, great credit to Malky, he's kept it going. There's no [Jay] Bothroyd or [Craig] Bellamy, those two players alone is a scary proposition.
"He's lost players yet he's done very well, maintaining the challenge at the top end of the table. I'm looking forward to seeing him again and hopefully comiserating with him at the end of the game."
Both Cardiff and Middlesbrough, with a win today, could move into 2nd place depending on West Ham's result at Upton Park.
Mowbray added: "It gives hope to everybody else that they (West Ham) are beatable, we just have to keep going for ourselves. It's good to have won back to back games, six points is fantastic at this time of year.
"I'm sure West Ham will be stung from their negative results so they'll be looking to get back to winning ways, of course, but I think all we're trying to to is keep winning points, keep racking them up, trying to win football matches, and get down to the real nitty-gritty stuff after the new year.
"Getting into February and March, 12 games left, you really need to find consistency and hope you get over the line.
"We're just trying to put ourselves in a position to do that at the moment along with another dozen clubs who are in and around the top six."
Cardiff v Middlesbrough
Saturday 17th December, ko 3:00pm.