Armer has attracted attention for his physical resemblance to Harry Maguire, with supporters drawing comparisons between the pair’s stature, movement and approach to carrying the ball out from defence.
Like Maguire, the teenager stands at 6ft 4in and is known for his strength in aerial challenges.
The centre-back’s promotion comes as Manchester United contend with a series of injuries. Luke Shaw and Kobbie Mainoo joined Noussair Mazraoui, Patrick Dorgu and Benjamin Sesko on the sidelines ahead of the trip to Madrid.
Manager Michael Carrick said the opportunity would reward Armer’s development rather than indicate a shortage of players.
“We’re not light on numbers, it’s good for the likes of Dan to sample it. He’s been around a long time and he’s worked so hard to get to this stage,” Carrick said.
Armer made an impression during Manchester United’s youth campaign last season, when Darren Fletcher’s Under-18 side reached the FA Youth Cup final before losing 2-1 to Manchester City. Carrick and assistant Steve Holland regularly watched the academy side during its run.
The youngster also featured in pre-season, including a match against Leeds United at Dublin’s Croke Park, where he faced England striker Dominic Calvert-Lewin.
Maguire has praised the academy players’ progress, saying: “Dan has been magnificent and, hopefully, he can continue to progress, keep enjoying working with us. There have been so many good performances from the younger boys.”
Armer is a Scotland youth international who has shown a willingness to learn, regularly asking coaches for advice and seeking additional video analysis of his performances.
He is expected to play a significant role for United’s Under-21s this season while continuing to train with the senior squad. A loan move could be considered if the right opportunity emerges, but the club’s current plan is to keep him within its development system.
The Atlético trip offers a valuable experience for a young defender whose progress has attracted growing attention. The comparison with Maguire remains a point of interest rather than a guarantee of a similar career, but Armer now has another chance to demonstrate his potential within United’s first-team environment.