What was it like being Keano's new team-mate?

The Bulgarian spoke to us about his participation in the charity fixture, which will raise funds for Manchester United Foundation, about playing with legendary former Reds skipper Keane during their time together at Celtic.

Keano, now a hugely popular TV pundit, joined the Bhoys in December 2005, after leaving United, and helped the Glasgow giants win the Scottish Premier League and League Cup during his short stint in Scotland.

Petrov will be representing Celtic in the 7 September clash after overcoming leukiema, which cut short his playing career, and is looking forward to what promises to be another special occasion.

He will be up against his fellow countryman Dimitar Berbatov, who has signed up for Bryan Robson's men, and has plenty of associations with United from the past, including crossing paths with Keane.

"You know, when he signed for Celtic, obviously we had to drive from the stadium to the training ground," said Stan. "So I’m sat in my car, sorting my boots out. And the next thing? Why Keaney jumps into the car.

"So I’m starstruck and, you know, he just went: ‘Drive’! And I was just lost for words. Well, this is Roy. So many things had been expected but he’s got a great sense of humour. An incredible person. We still keep in touch and it will be great to see him if he does sign up for the game.

"He's definitely a character and I think football needs characters," added Petrov. "Football needs people like Roy Keane, you know. He’s direct. He’s very forward and, sometimes, you know, well, there is nothing wrong with that.

"I enjoy watching him on the telly. I speak with him sometimes about football and about certain things in life and, you know what, he played in my [charity] game as well, which was great to see. He's still looked good and you can see his awareness and his passes, and the movements he was demanding."

Petrov has been involved with several charity matches, raising funds for cancer research and other worthy causes.

"I've got my own foundation and I know how important it is," he explained. "I know how vital it is and especially with the youth today, you know. But the foundation are helping with great resources and with mental support. So it's incredible to be part of it and to be part of those games and to help with everything we can.

"I’ve had a few games. Last year, I had one in Bulgaria as well as the one I had in Celtic, at Celtic Park as well. So, for me, it’s incredible. You have got a lot of work going into it but the satisfaction afterwards, it’s about who you’re helping and what you do for other people. Many of the players, they’re going to take part in the game on 7 September at Old Trafford and they’ve been through difficult times. So we all know how important it is to help others and how important it is to support others as well.

"So, for me, that game was very special at Celtic Park. Every game is emotional. I mean, the football was taken away from me because of an illness and I know how important football is. And, every time I touch the ball, I can still run. I can, you know, enjoy myself."

Click here to buy tickets for the Legends game: United v Celtic on 7 September.