Ruben Amorim has revealed that he wanted to take the Manchester United job at the end of the season but was told the opportunity was “now or never”.
Amorim was confirmed as United’s new head coach on Friday and will formally take up the position on November 11.
And speaking after Sporting Lisbon’s 5-1 Primeira Liga victory over Estrela on Friday evening - their first match since the announcement - he revealed his request to delay the move was rejected.
"The season started, we started very well, and then Manchester United came, they pay above the compensation clause and the president defends the club's interests," Amorim said.
"I never discussed anything with the president. For three days I said I wanted to stay until the end of the season, but then I was told it was not possible.
"It was now or never, or Manchester would go for another option. So, I had three days to make my mind up, to make a decision that changes radically my life."
United have agreed a compensation package with Sporting worth around £10.6million for the 39-year-old, who has signed a two-and-a-half year contract with the option of another year.
And Amorim - who won two Portuguese league titles at the Lisbon club, ending a 19-year wait - insisted he had turned down other opportunities before United came calling.
"I've had other opportunities - the president and [director of football] Hugo Viana can confirm this,” Amorim added.
“It's not the first or the second time that I have been requested by another team and I don't want another team.
"After Sporting I wanted that one, Manchester, and I want that context because that context allows me to do things my way and the club believes me that way.
"There's a time when I have to take a step forward in my career. That's what happened. It was harder for me than to any Sporting fan, believe me, but I had to do this."
“Now I go home happier because I have explained. People say 'it's about the money', but there was another team that wanted to hire me before and they paid three times more than Manchester.
"It was the best phase of my life. Everyone at Sporting knows. I understand the disappointment of the fans but today is not the farewell. We still have two important games against Manchester City [in the Champions League] and Braga [in the league] to maintain the lead."
Ruud van Nistelrooy will continue in interim charge of United for their next three fixtures - with Chelsea up next in the Premier League on Sunday.
Van Nistelrooy’s future under Amorim is unclear with the Portuguese boss revealing his desire to bring his backroom staff at Sporting with him to Old Trafford.
"I will take my staff with me,” he added. “That was always one of my conditions. I brought them with me since Casa Pia.”
Amorim has already been linked with a £70m move for Sporting defender Ousmane Diomande as he plans to implement his favoured 3-4-3 formation at United.
However, the former Braga boss has insisted he won’t be raiding his former club for players in the January transfer window.
"[Viktor] Gyokeres costs 100 million and it's very difficult,” he said after the striker’s latest four-goal haul. “I'm not going to pick up any Sporting player in January.”
