Chelsea have been informed that Cristiano Ronaldo could be willing to join them, but the club are yet to decide whether to make a formal offer.
Ronaldo has informed United of his desire to leave in pursuit of Champions League football, but there are few realistic options for the 37-year-old, who earns around £500,000 a week.
Bundesliga and Ligue 1 champions Bayern Munich and Paris Saint-Germain have been mooted as possible destinations.
And sources have told ESPN that contact has been made between Ronaldo’s representative, Jorge Mendes, and new Chelsea chairman Todd Boehly.
Boehly, who is also acting as interim sporting director following the exits of Marina Granovskaia and Petr Cech, is thought to be attracted to the idea of signing such an iconic figure as Ronaldo even at this late stage of his career.
However, sources have told ESPN that some at the club doubt whether head coach Thomas Tuchel is sold on the idea given that he has specific plans to remodel his forward line.
Striker Romelu Lukaku was loaned back to Inter Milan just a year after Chelsea paid €115 million for him, because of an inability to press effectively and a breakdown in relations.
Ronaldo scored 24 goals in 38 appearances for United, but rumours persisted of dressing room disagreements, while former interim boss Ralf Rangnick is thought to have advised letting the Portugal forward leave in January due to his inability to adapt to his preferred pressing style.
United continue to insist they are not interested in letting Ronaldo leave, despite the player being given permission to miss training on Monday due to “family reasons,” but Chelsea will now consider whether to explore the finer points of a deal.