Cristiano Ronaldo's shock demand to leave Manchester United has thrown Erik ten Hag's plans into disarray as he scrambles to contain the fall-out from the Portugal star's power play.
Just one year after returning to United in a blockbuster move from Juventus, Ronaldo has already grown so disenchanted that he is trying to force his way out of Old Trafford.
The 37-year-old is reported to have told United he wants to be sold, with his agent Jorge Mendes said to have held talks with Bayern Munich, Chelsea and Napoli as he seeks a club capable of satisfying Ronaldo's ambitions.
Ronaldo's frustration mounted throughout a turbulent campaign that saw United go through three managers as they finished a disappointing sixth in the Premier League.
Although Ronaldo was United's top scorer with 24 goals in all competitions, his side ended the season trophyless and failed to qualify for the Champions League.
The prospect of playing in the Europa League is hardly appealing to a five-time Ballon d'Or winner who has lifted the Champions League trophy five times.
Ronaldo has one year remaining on his contract and United insist the former Real Madrid forward is not for sale.
Ten Hag had expressed excitement at the prospect of working Ronaldo, but might have to plan a future without his most decorated player.
If Ten Hag had hoped to persuade Ronaldo to drop his transfer demand, the former Ajax boss won't have been encouraged by the star's absence when the rest of United's internationals arrived for the start of their pre-season training programme on Monday.
United are due to fly to Thailand on Friday for their tour of Asia and Australia.
If Ronaldo misses the trip, it would seem almost certain his second spell at United is destined for an abrupt end.