Shakhtar Donetsk star Fred has been tracked by Manchester United, who are aiming to make some world-class additions to their squad.
With Michael Carrick retiring and Marouane Fellaini’s long-term future in doubt, a midfielder has been earmarked.
Reports have suggested that Fred is increasingly close to completing a £53million switch to Old Trafford.
But now according to The Sun, Mourinho has sent an ultimatum over Fred.
It is suggested he has iterated to the board he wants a deal to be done latest by next week or not at all.
South American fooball expert Tim Vickery revealed earlier this week that Fred, who was linked to Manchester City in January, is “very excited” about coming to the Premier League.
He said: “I enjoyed watching him on the way up at Internacional.
“He’s a busy little left-footed midfielder. Very dynamic, and he’s got some quality. He’s developing as well.
“I could understand City’s interest. When they played Shakhtar in the Champions League, Pep Guardiola was very impressed with him.
“You could see Fred fitting into a dynamic Manchester City midfield. He’s almost like a smaller left-footed version of Fernandinho.
“To my surprise, it seems City have dropped aside and United have come in there.
“I know that Fred is very excited about the prospect of playing for a top club in the Premier League.”