Jerome Boateng bluntly told Jose Mourinho that he does not believe Manchester United can win the Champions League as he rejected a move to Old Trafford, according to reports.
The Bayern Munich centre-back was the subject of a late transfer move by United as Mourinho looks to bolster his backline before Thursday's Premier League deadline.
The Bundesliga champions were believed to be ready to cash-in on Boateng, but the 29-year-old personally phoned Mourinho on Tuesday to say he would not be moving to Old Trafford.
Now The Guardian have revealed that during their conversation Boateng told Mourinho that he has more faith in Bayern's project to deliver the silverware he craves.
Boateng is desperate to win the Champions League and is not convinced United will provide him with the platform to do so.
He believes his chances of claiming European glory for the second time - having won the tournament in the 2012/13 season - are significantly higher if he stays with Bayern.
French giants Paris Saint-Germain are still interested in signing Boateng, and have until the end of the month to do so, and the defender would consider a move to PSG as they are genuine Champions League contenders.
Mourinho is still desperate to sign a new centre-back before Thursday's deadline and hopes to finally prise Toby Alderweireld away from Tottenham Hotspur.
If Spurs cannot be convinced to let the Belgian leave, United are also looking at Barcelona's towering centre-back Yerry Mina and Leicester City defender Harry Maguire.