Scott McTominay wants to repay Manchester United's faith and patience by making a first-team impact like fellow late developers Marcus Rashford and Jesse Lingard.Having just turned five when he caught United's eye at the development centre in Preston, the attacking midfielder progressed through the ranks and in May made his first-team debut aged 20.That appearance off the bench at Arsenal was followed by a starting role in the home win against Crystal Palace in the Premier League finale, before McTominay was selected by Jose Mourinho for their pre-season tour.After impressing in the United States, in particular off the bench against Real Madrid, and scoring his first senior United goal against Valerenga, he is now in line to be involved in a competitive match for the first time this season as Burton visit in the Carabao Cup third round."It's crazy when you think back all them years to when you're five years old going to the development centre, and then going all the way through the ranks," McTominay told Press Association Sport."It honestly is a dream come true for me to be playing in the first team, and playing against teams like Real Madrid."But obviously you just want more and more of that and that is the main thing for my career: to be playing in them big games, in competitive games and just do my best and hopefully see where it takes me."The fact the Lancaster-born 20-year-old was not part of United Under-23s' draw at Chelsea on Monday indicates he is likely to be involved on Wednesday, when Luke Shaw, Michael Carrick and Sergio Romero will be hoping to get their first minutes of the season.Mourinho will not be taking it lightly against Sky Bet Championship side Burton, though, as the likes of Rashford and Lingard push for a start - players McTominay has long looked up to.Both players have gone on to establish themselves having been late physical developers just like the midfielder, who may be an imposing 6ft 4ins now but just two-and-a-half years ago stood at 5' 6''."Marcus and Jesse are such role models to me because they were late developers like I am," said McTominay, who used to share number 10 duties with Rashford at Under-16 level."Not everybody is born at 16 years old ready to go straight into the Premier League and they're physically ready."At 16 years old, I was like a really young boy and it takes time for boys to blossom and that is why this club was so patient with me. Not every single boy is physically capable of going and playing in the Premier League at such a young age. "Michael Keane is another one, a brilliant example, who is doing so well now. He was struggling when he was 18. He was growing, he was changing."You can't tell anything in football until it is done."I still personally think I've got a long way to go with my physique, I am still quite slim. I am not the finished article physically. Nowhere near. But you just have to keep working hard every day and hopefully improve on all that and see how it goes." Such development led clubs to express an interest in taking McTominay on loan over the summer, but he stayed at United under the guidance of Mourinho."Things he does say stay between me and the manager, sort of thing, but a lot of it is help and advice, really," the midfielder, eligible for England and Scotland, added."It's all like when we go out on the pitch, what I can do better, things that I can improve on and he is brilliant for that with young players."He's top - he's perfect for a manager and that's why he is manager of Man United. He's a really good guy."