Manchester United has seen their attempt to appoint Rúben Amorim as Erik ten Hag’s successor held up by negotiations with Sporting Lisbon regarding a 30-day notice period.

The 39-year old has been picked by the club to replace the sacked Dutchman, and have informed the Portuguese champions of their readiness to meet Amorim’s €10m (£8.3m) release clause so he could be around for Sunday’s visit of Chelsea but this may not be possible unless there is a breakthrough in discussions.

Manchester United’s key figures are in Portugal as talks continue with Sporting. However, the crux of their discussions remains the backroom staff Amorim may want to bring with him to the club.

The Red Devils will be busy across the next one month with a Premier League ties Chelsea, Leicester, Ipswich and Everton but the Manchester United hierarchy is confident Rúben Amorim’s appointment will be confirmed before December.

Meanwhile, Amorim insists he remains focused on helping Sporting Lisbon emerge as double winners of the league and the league cup this campaign. He also added that nothing has been confirmed.

“Nobody knows if it was my last match. It’s something still not decided. When and if I make that decision, I will say it. The only thing concrete right now is the club’s statement, but when I have something more concrete, I will tell you because everything is down to my decision.” Amorim said.

Sporting play at home to Estrela Amadora in the league on Friday night, which could potentially be his final game in charge of the Portuguese side if his discussion with Manchester United goes through.

In the interim, Ruud Van Nistelrooy is expected to lead United against Chelsea on Sunday if the Amorim appointment hasn’t been concluded by then, but it’s unclear whether the former PSV boss will remain at the club once the Portuguese arrives.