Mourinho was in typical box-office form as he welcomed Erik ten Hag's team to Turkey and is no doubt relishing the chance to add to their difficult start to the season. The Portuguese spent an eventful two-and-a-half years at United before he was sacked following a poor run of form in December 2018.
The pressure on his successor, Ten Hag, was lifted slightly by Saturday's 2-1 victory over Brentford in the Premier League. The result ended a run of five games in a row without a win, which included draws against FC Twente and Porto to start their Europa League campaign.
Ten Hag's side can expect a hostile atmosphere in Istanbul and United have not won any of their last four trips to Turkey, including a dramatic 3-3 draw away to Galatasaray last season. Follow live updates from the Europa League clash between Fenerbahce and Manchester United, below