Peterborough United manager Darren Ferguson says his side's League One play-off semi-final win proves they are ready for the big stage.
Posh's 2-0 second leg victory over MK Dons on Thursday was enough to see them into the final with Huddersfield.
Ferguson's side had lost the first leg 3-2 at Stadium MK four days earlier.
The Scot told BBC Radio Cambridgeshire: "After Sunday we thought 'we can sing in the shower but can we sing on the stage?' We think we can now."
Ferguson will now lead Posh out at Old Trafford, the ground where he started his playing career and where his father, Sir Alex, has achieved incomparable success with Manchester United.
"I said to the players 'you'll never forgive yourselves if you have to watch on your holidays Milton Keynes and Huddersfield walking out at Old Trafford'," he added.
"We would never forgive ourselves, but fortunately it's going to be us.
"I do actually think you can go to the final and enjoy it.
"I don't really know if you can enjoy these semi-finals but you enjoy the final."
The club's owner Darragh MacAnthony, who has overseen two promotions and last season's relegation from the Championship, was overjoyed after the game.
"This is probably the best atmosphere I've witnessed at London Road," he said.
"I've known the club for a long time, we had a horrible end to the season last year, and if you had said to me then, 'Darragh, will you take one more game to get your place back in the Championship?', most people would have bitten your hand off.
"We've got a week now to prepare and go to Old Trafford and play a great game of football against Huddersfield."
The experience of suffering play-off heartache left Dons boss Karl Robinson deflated, but bullish about next season.
"Our players have given us everything, it's just not enough," he told BBC Three Counties Radio.
"It's onwards and upwards for us, it's a positive night in relation to where we want to go.
"This has lit something in my head and heart - I do not want to feel this pain again and from that I will come back a stronger manager and we'll come back a stronger team and club."
It was a sentiment reflected by his chairman Pete Winkelman, who suggested the Dons should be aiming for automatic promotion next term.
"We've definitely got what it takes to move up, four times in the last five years we've either been promoted or in the play-offs," he said.
"Maybe we've got to concentrate on that first or second place as that gets you safely into the next division."