Ruben Amorim has said he is aware his job will be at risk if he fails to reverse Manchester United’s alarming slide and acknowledged supporters are “tired” of the team’s shortcomings. Amorim recognises the volatile state of management and is determined to thrive on the pressure.

The coach said he is not immune from danger because United paid €10m (£8.3m) to release him from his contract at Sporting in November and knows he must win to prevent scrutiny from building. Amorim’s successor at Sporting, João Pereira, was sacked this week after eight matches in charge.

Related: Manchester United ‘just have to survive’ says Ruben Amorim after Wolves loss

United have lost five of their past seven matches in all competitions, including four of their past five in the Premier League. Defeat at Wolves on Boxing Day dropped them to 14th, eight points above the relegation zone and 11 off fourth-placed Arsenal, leading Amorim to dismiss United’s chances of qualifying for European football.

“The manager of Manchester United can never, no matter what, be comfortable, and I know the business that I’m in,” Amorim said. “I know that if we don’t win, regardless of if they paid the buyout [for me] or not, I know that every manager is in danger and I like that. I like that because that is the job. You can argue that I have been here one month and I’ve had four training [sessions], but we are not winning. That is the reality and I’m quite comfortable with that.”

United have conceded goals to corner-takers in two recent matches, the Carabao Cup quarter-final defeat at Tottenham and at Molineux. While Amorim felt his goalkeeper André Onana was impeded at Wolves he stressed his players “must not cry about it” and instead suggested United should be inspired by their opponents. “We have to focus on doing the same thing to the opponent – that is my goal,” he said. “We just have to copy.”

Asked about the challenge of hosting Newcastle on Monday after the 3-0 loss at home to Bournemouth in their previous match at Old ­Trafford, Amorim added: “We have to fight against everything because our supporters are always there, but they are tired of this moment. We have to expect that any play from Newcastle near our box is going to make the stadium nervous and our players have to cope with that. We want to be competitive and try to win the game.”

Meanwhile, former United and Sporting superstar Cristiano Ronaldo has backed Amorim to succeed at Old Trafford. “He did a fantastic job in Portugal with my Sporting,” he said. “The Premier League is a different beast, it is the most competitive league in the world and it will be tough. They will continue the storm but the storm will finish and the sun will rise. Fingers crossed things will be good with him and I hope the best for Manchester United as it is a club I still love.”

The Al-Nassr forward also addressed the long-term problems at United and talked about owning a club himself one day. “I said this one and a half years ago and will continue to say, the problem is not the coaches,” he said. “I always give this example, it’s like the aquarium – if you have a fish that is sick and you take him out and fix the problem but put him back in, they will be sick again.

“This is the problem of Manchester United, it is the same. The problem is not only the coach, it is much more than that. If I was owner of the club I would make things clear and adjust what I think is bad there. I am still very young and have so many plans and dreams ahead, but mark my words I will be the owner of a big club, for sure.”