The Red Devils boss has gone on holiday following Wednesday’s Europa League final triumph.
And after securing Champions League football for United, the Portuguese has left clinching transfers up to Ed Woodward.
Mourinho has already provided the club with his top targets, and it is set to prove a costly summer at Old Trafford.
According to the Daily Mail, United are on course to undergo a £300million spending spree, with bolstering their attack the focus.
United have been criticised in recent years for their approach and lack of goals since Sir Alex Ferguson’s departure.
And even under Mourinho they struggled in front of goal, with Zlatan Ibrahimovic comfortably ending as their top scorer.
Jose Mourinho wants four star players added to his Manchester United squad this summer
United’s spending could reach £300m for just four players
As a result, Griezmann is being pursued as their No1 priority, with the Atletico Madrid striker edging closer to Manchester.
He wants his future sorted within the next two or three weeks ahead of his honeymoon, and United are prepared to meet his £86m buyout clause.
Meanwhile, forwards Romelu Lukaku and Andrea Belotti are still wanted it seems.
The Daily Mail add Jose Mourinho is targeting the Everton and Torino goalscorers too, which is why United’s spending could reach £300m for just four players.
Manchester United summer transfer targets Wed, May 24, 2017
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Express Sport takes a look at who could be on Manchester United's shopping list this summer
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Antoine Griezmann is set to be one of those big-money additions at Manchester United
The final one Red Devils academy graduate Michael Keane, with Burnley wanting £30m for the central defender.
Manchester United chiefs are said to expect this to be a transfer window of huge spending from across Europe due to the TV revenues and other factors.
At Old Trafford, France international Griezmann would be considered the stellar signing.
But Serie A star Belotti, who has an £86.6m release clause, and the Premier League’s top marksman Lukaku, who has a £100m price tag, could both cost more than Griezmann.