Manchester United have reportedly already approached Sporting Lisbon boss Ruben Amorim after sacking Erik ten Hag.
Ten Hag was dismissed on Monday, a day after United suffered their fourth Premier League defeat of the season at West Ham, dropping to 14th in the table. They have won only one of their last eight games in all competitions.
Within hours of that announcement being made, reports said the Old Trafford club were willing to pay the 10 million euros (£8.3million) release clause to secure 39-year-old Amorim, whose Sporting Lisbon side sit top of the Portuguese table. United declined to comment when contacted by the PA news agency.
Amorim has won two Portuguese titles and two League Cups with Sporting since joining the club in March 2020.
In recent weeks he has been suggested as a future Manchester City manager, with Sporting's Hugo Viana, a close friend, due to move to the blue half of Manchester as the club's new director of football next season.
Sunday's controversial 2-1 defeat at West Ham, in which Jarrod Bowen's disputed late penalty proved decisive, was the final straw for Ten Hag. Speculation over the Dutchman's future had regained intensity in recent weeks after the 54-year-old remained in the role at the end of last season.
A club statement shortly before noon read: "Erik ten Hag has left his role as Manchester United men's first-team manager. Erik was appointed in April 2022 and led the club to two domestic trophies, winning the Carabao Cup in 2023 and the FA Cup in 2024.
"We are grateful to Erik for everything he has done during his time with us and wish him well for the future."
Ruud van Nistelrooy has been put in interim charge ahead of Wednesday's Carabao Cup tie at home to Leicester.
Ten Hag survived a summer review at United, buoyed by having beaten Manchester City to lift the FA Cup in May, but after only three wins from nine league games the club have swiftly had a rethink.
United indicated it was a unanimous and collective decision, albeit a difficult one to take, PA understands.
The club had wanted to give Ten Hag the chance to work within a new sporting structure set up over the summer, but results and performances have forced their hand.
It is understood the club's hierarchy had not seen enough progress in Ten Hag's side to believe they were on the right path to challenge again for the Premier League title.
After replacing interim manager Ralf Rangnick, Ten Hag ended the club's six-year wait for a major trophy in his first season when his side beat Newcastle in the Carabao Cup final.
The former Ajax boss also led United to a third-placed top-flight finish, but his second season saw United knocked out of the Champions League group phase before finishing eighth in the Premier League.
Despite rampant speculation that he would be sacked in the summer, the club opted to trigger a contract extension until 2026 after carrying out an extensive review.
Ten Hag, United's fifth permanent head coach since Sir Alex Ferguson retired in 2013, had led Ajax to the 2018-19 Champions League semi-finals and also won the league and cup double with them in 2018-19 and 2020-21.
