The Glaswegian said: "When you're a wee boy all you want to do is play or be involved competitively in the two major stadiums in the UK.

"To be able to do that will be a special moment for the family, that's why I came up here.

"To be able say I've done Wembley and Hampden is up there with what I wanted to do as a wee boy in Glasgow.

"That will pass in a few days because I'm greedy and I want more.

"Now we're in a semi-final, I want to attack it and get to a final.

"But right now I will take a moment to think about doing Wembley and Hampden in a career."

Mellon praised the United fans who turned up on Saturday to give the players an encouraging send-off from Dundee.

He said: "The send-off we got from the supporters was terrific – socially distanced and in an orderly fashion, of course – that really set the tone for the mentality coming up here.

"We spoke about it before the game, how important it was to do it for the supporters.

"The players did it for them, for their families and for the club – they were fantastic."

After a Scottish Cup penalty shoot-out win over Livingston and 1-1 draw with Celtic on Wednesday night, new Dons boss Stephen Glass suffered his first defeat and claimed his side were physically and mentally fatigued.

He said: "It's very disappointing. We came into the game hoping to perform as we have done in the last couple of games, but I think you saw that the group looked dead on its feet.

"They have given us everything they have in the last two games and it didn't look like they had anything left to do the things we needed them to do against a United team that came full of energy and quality. We didn't handle that challenge.

"I didn't think we were looking forward quickly enough and when it went back, United pressed up and we didn't handle the pressure.

"We looked mentally tired and like we couldn't play under that level of pressure for a third time in the week.

"That's something we need to address, build and make sure that it doesn't happen again once we've had more time with the players.

"You learn what is required to handle three games in a week; you learn the players who are capable of doing it and the ones that are not.

"But they have given us everything. Their professionalism has been first class and we didn't have the choice to make five or six changes, without throwing lots of young players into a game of that magnitude.

"The group is what it is and that's why we are here, to assess it ahead of next year."