Ruud van Nistelrooy said he was “hurt” that Ruben Amorim’s arrival at Manchester United triggered his exit after a promising interim spell. Van Nistelrooy impressed during his four games in charge after the sacking of Erik ten Hag, opening doors to various jobs in England and overseas, with Leicester winning the race for his services. Van Nistelrooy’s first game in charge of his new club is at home against West Ham on Tuesday.

Van Nistelrooy said that although he was disappointed to leave United he quickly came to terms with his departure after amicable talks with Amorim and is ready to “work around the clock” to lift Leicester, who are a point above the Premier League relegation zone after Saturday’s 4-1 defeat at Brentford. The Dutchman left Old Trafford with his reputation enhanced, “astonished” at the spike in interest.

“I was disappointed, yeah, very much so, and it hurt that I had to leave,” the 48-year-old said. “The only job I would take as an assistant was at United because of the bond that I have with the people in the club and the fans. But in the end I got my head round it because I also understand the new manager. I spoke to Ruben about it, the conversation was grateful, man to man, person to person, manager to manager, and that helped a lot to move on and straightaway get into talks with new possibilities which of course lifted my spirits.”

Van Nistelrooy, appointed on a two-and-a-half-year contract after rounds of discussions in London with Leicester’s chairman, Aiyawatt Srivaddhanaprabha, and the club’s director of football, Jon Rudkin, said the ultimate target for a team promoted as champions last season is survival. Leicester are 16th in the Premier League after a run of six games without a win and Van Nistelrooy said he is ready for a relegation scrap.

“I think I have to go back to my first three years of my playing days in the Dutch championship [Eerste Divisie] … many people forget about that,” he said. “They see ‘Real Madrid, Manchester United’, but my first three seasons in the Dutch second tier were with a club called FC Den Bosch, and my first season as a professional when I was 18 we were 18 of 18 [in the table]. So I know what it is to fight. I know what it is like when you have to fight for every result and where you have to work around the clock to get better, to improve, that’s what I always was like in my playing days and also managing. I don’t have a problem with that, growing up and getting better bit by bit. That’s how I am.”

Van Nistelrooy stressed he will prioritise results over style of play in his bid to pull Leicester clear of trouble, the Dutchman insisting he is not “the romantic type of manager”.

Asked about what supporters can expect from Leicester under his leadership, he replied: “I’m thinking of one thing before any game I prepare, and that’s winning. When you play top teams in the Premier League, mid-table teams or lower-ranked teams, it sometimes requires a different approach. The style of play is adjusted on: ‘How can we win here?’

“I’m not the romantic type of manager who puts style in front of results. I love style, I love having the ball, I love creating lots of opportunities, pressing a team high, because you have more of the ball, but we are facing opponents here and we’re not the dominant side in this league. We approach every game in this league to win. Any approach for that will be made.”

Van Nistelrooy will manage Jamie Vardy, who broke his goalscoring record in 2015, the Leicester captain becoming the first player to score in 11 successive Premier League matches. “It’s a problem, of course, that he broke my record … I told him straightaway: ‘We have a big issue we need to get out of the way before we can even start together,’” he said. “I think I beat him to it.

Back in the day I made a tweet about breaking the record and wishing him well and then nine years later I am here. It’s weird how things go sometimes.”

Van Nistelrooy said his experience of playing under authoritative managers in Sir Bobby Robson, Sir Alex Ferguson and Fabio Capello at PSV, United and Madrid respectively serves him well as a manager. “Thank God I worked with them, because it’s lessons you don’t learn in a chorus book,” he said.