According to Mourinho, the players, organisation, and the ambition of the club were the three biggest problems of Man United.
This he said in response to Manchester United finishing the 2018/19 Premier League season on the sixth position with 66 points from 38 games.
Speaking with L’Équipe, the Portuguese said: “The problems are there, you can say that these are the players, the organisation, the ambition.
“I only say that I cannot say yes when you ask if Paul was the only one responsible.”
Mourinho added: “I know Manchester United, I know it’s a club with an incredible story. With ambitions that are in tune with his past but not with today’s potential.
“I said, nine, ten months ago, that after winning eight Championships, finishing second with Manchester United was perhaps my greatest achievement. Now, people understand.”