#3 Opting for long ball tactics
United were doing very well in the first half. The movement was slick, the front three were combining very well together, they were switching places and giving the Wolves defence a pretty hard time.
Fred and Pogba were moving the ball nicely, finding spaces, sending in good balls. The movement around the penalty area was impressive and United were actually playing attractive, effective football that had kept Wolves almost out of the game.
After the break, Mourinho opted to change the formula that had been working so well and instead, tried to find a way through Fellaini, off all people. The problem with the Belgian is that there are no other facets to his football other than receiving the ball on his chest or heading the ball to a teammate, both of which he is quite good at and as a result, this tactic is effective only sporadically.
For a team like United, with so much quality on the ball, firepower and speed on the ranks, there was no need to deploy the long ball game from the start of the second half, especially when they were leading 1-0! The resultant outcome was zero, United rarely looked like they would score again. Lukaku did not receive the service he deserved and United failed to find the goal.
Whatever Mourinho tried to achieve backfired and put him in a mess, all because he changed tactics when it was not needed.