With his breezy manner, shock of jet-black wavy hair and declaration that “we choose our way 100%”, Ruben Amorim exuded the fresh energy Manchester United need in his debut media conference at a crammed Jimmy Murphy Centre.

With only four points to third place, there is a golden chance to transform the season. Yet the issues Amorim wrestles with are the club he has walked into and the squad he has inherited.

The 39-year-old was enthusiastic about his “many meetings” at United and was firm regarding his belief in the players he drills on the pitches outside. Wearing a club tracksuit top with red front panels and blue sleeves, Amorim was as open under questioning as Erik ten Hag could be taciturn. But different personalities did not prevent the Dutchman, David Moyes, Louis van Gaal, José Mourinho and Ole Gunnar Solskjær from being sucked into the black hole of the post-Sir Alex Ferguson United.

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It is a vortex that cannot be comprehended until experienced. The above quintet can point to how mismanagement at executive level caused the fatal corollary of muddled player recruitment. So Amorim’s task is to work the oracle with a squad that apart from Bruno Fernandes, Kobbie Mainoo, Lisandro Martínez and Marcus Rashford (if he can rediscover consistency) is average.

Asked why he believed in a group that got Ten Hag the sack, Amorim said: “The only thing I ask: hard work and you have to believe in the new idea. And I felt that. Until they prove me wrong, I believe in the players.”

As United’s new football chief, Sir Jim Ratcliffe was billed as the required boardroom reset. But after failing to axe Ten Hag in the summer, United invested £200m on five footballers wanted by the manager – Manuel Ugarte, Leny Yoro, Matthijs de Ligt, Noussair Mazraoui and Joshua Zirkzee – before a puzzling Ratcliffe U-turn removed the Dutchman last month.

So a reasonable view is that the minority owner and his chief executive, Omar Berrada, and sporting director, Dan Ashworth, are yet to show spectacular improvement on the two previous power axes of Richard Arnold/John Murtough and Ed Woodward/Murtough; and that Amorim may end as the latest man in the Old Trafford hot seat ejected by dodgy decisions from above.

For now, he has a unit that includes 14 Ten Hag recruits who have to be weaved into his 3-4-3 along with Fernandes and Rashford, who predated his predecessor and whose maverick talents are vital yet tricky to fit into a cohesive unit.

Amorim presented the challenge this way: “I don’t know about repair but we have space to grow as a team. We have to improve in a lot of areas: the understanding of the game, I know it’s a different way of playing, and we are changing in the middle of the season.

“We have to improve the physical aspect. And that’s it. I don’t know how long it will take. I know when you are in Manchester United you have to win games. So I will not tell you that I need a lot of time. It’s a great league, it’s the strongest league in the world and we have to improve a lot to try to win it. So what I can say is we have to win games to win time and then to win titles.” This is what he is being paid the thick end of €10m (£8.3m) a year for.

Ten Hag finished third in his opening season but this was achieved with a misfiring attack that managed only 58 goals and United had a goal difference of 15, the division’s sixth-best. The key then was Rashford’s 17 Premier League goals, so reviving a forward who packs pace, height, strength and verve is as high on Amorim’s list as fitting him and Fernandes into his unfamiliar shape.

Of this, Amorim said: “It’s not revolution because football is not so different with five players in the back, three players in the back or four players in the back. I cannot say evolution because we will have to wait and see but we will play a different type of football.

“We have our ideas. I’m not saying these are the best ideas, but it’s our way of seeing football. It’s not evolution or revolution, it’s a change in the way we play football. We lose the ball too often and we have to keep the ball. We have to be better running back. That is clear for everybody. And we have to be very good in the details. Sometimes we are hoping to change a lot of things, big things.

“It’s [also] the small things and we are here to improve on the small things, the way we see football, play as a team. Understanding the game in one way, that is the focus. I can tell you in the small things I can help these players a lot.”

Related: ‘He’s ready’: Ruben Amorim’s rapid rise from obscurity to Premier League

The Portuguese, who fielded questions from nine journalists who flew in from his homeland, will have to if he is to achieve United’s holy grail of a 21st championship. A zesty charisma will help. It was on display again when he was asked about his compatriot Mourinho.

“I’m different,” Amorim said. “You looked at Mourinho and you felt he can win everywhere. He was European champion. I’m not European champion. I’m a different guy in a different moment.

“Football nowadays is different and I am the right person at the moment. I am a young guy, I understand the players, so I try to use that to help my players. It is still the best club in England and we want to win.”