Manchester United boss Ruben Amorim explained that the presence of his other strikers and wanting to manage expectations were the reasons why Chido Obi was completely left out of the Red Devils' Europa League squad. United may be left feeling red-faced in hindsight, having omitted the 17-year-old from their squad list for the competition.

Obi was not registered in September and Utd left him out again when submitting a revised list for the knockout stages last month. Youth players can feature on the B-List, but Obi is only eligible for the A-List after joining the club from Arsenal last summer. Obi made an immediate impact when introduced off the bench in United's FA Cup tie with Fulham, getting on the end of three big chances in his 52 minutes on the pitch.

The teenager was a breath of fresh air compared to Rasmus Hojlund, who has not scored a single goal since December, while Joshua Zirkzee has improved in a deeper role.

But the two young forwards alongside the plan to temper expectations regarding Obi played a factor in opting against including him for European matches.

"A different context," Amorim explained in his pre-match press conference. "In that moment, Ras (Hojlund) and Josh (Zirkzee) playing in same position, try to manage all the things, even expectation of the kids. We choose different players."

Amorim also revealed that he wanted to include youngster Harry Amass in his travelling squad to take on Real Sociedad, but could not due to his participation in the FA Youth Cup epic against Arsenal.

Having decided against picking more academy players to join his threadbare squad, the Portuguese boss added: "I am trying to manage everything, it is a big step for them. I am trying to think about every aspect. I am not thinking about what it will look like with their friends and the media."

Amorim was handed a further blow when Manuel Ugarte and Harry Maguire missed training on Wednesday, leading him to rule them out against La Real: "We are being careful. They cannot play the game."

With the Europa League becoming United's last chance at success this season, while languishing 14th in the Premier League table, Amorim hit back at suggestions that his 3-4-3 system is to blame for their dismal set of results.

"I think the system is not the problem, it is the way of playing," he said. "We have a lot of problems and we are trying to work on the problems. Every system needs different characteristics. I am still really confident. I will not change that [my formation]."

Sociedad represent another opportunity to get back to winning ways, but United will have to make do without perhaps their most threatening striker in Obi, after what could end up being a costly blunder if Hojlund's form does not improve.