However, with Tottenham keen to hold on to their manager and Chairman Daniel Levy reportedly having slapped a £50 million price tag on him, United are keen to sound out potential suitors to the role - like Atletico Madrid's Diego Simeone.
Another salient fact working in United's favour in this situation is that Simeone only has 18 months left on his contract with Atletico, and is still in the process of negotiation.
However, United are increasingly anxious that the Argentine could remain in north London and are considering alternatives, including caretaker manager Ole Gunnar Solskjaer and even England boss Gareth Southgate.
Since taking charge of Atleti in 2011, Simeone has won La Liga, the Copa del Rey and two Europa League crowns, as well as reaching a couple of Champions League finals.
He has hinted at leaving Atletico previously, though in relation to Inter Milan, saying: 'I must have said it 2,000 times about my return to Inter.