It looked like a switch had been flicked at the Cardiff City Stadium on Saturday evening: Manchester United, free from Jose Mourinho’s management, were suddenly playing like Manchester United again.Ole Gunnar Solskjaer’s temporary spell in charge of the Red Devils got off to the perfect start.United secured an emphatic 5-1 victory over their Welsh opponents; the first time they’ve scored five goals in a Premier League match since Sir Alex Ferguson’s final game in charge back in May 2013.Goals from Marcus Rashford, Ander Herrera and Anthony Martial put United 3-1 up at half-time.Jesse Lingard then added gloss to the scoreline by helping himself to a second-half brace.Mourinho didn’t watch the match live - he was spotted back in Portugal watching his hometown club Vitória de Setúbal lose 2-0 to Santa Clara - but he must have been bewildered to see the full-time scoreline from Cardiff.The Portuguese tactician left United’s board with little choice but to sack him after a string of poor performances.It was also clear that he’d fallen out with many players inside the dressing room.Wayne Rooney, who brought an end to his 13-year career with United following his first season working with Mourinho, provided revealing details about the 55-year-old’s man-management skills (or, rather, lack of) on BT Sport.United’s all-time leading goalscorer was asked by BT Sport host whether Mourinho did enough to keep players onside, to which he replied: “In my opinion, obviously being there for a year with him, he didn’t."I think that was the one surprise I had, that the communication with the players wasn't as much as it could have been.“When you leave a player out of a game, it gives them freedom of the mind when the manager says ‘I’m leaving you out for this reason or for that reason’ - but the players didn’t get that and the most difficult thing for a player is trying to work out why you’re not playing.”Asked if he tried to get answers out of Mourinho, Rooney continued: “Yeah, of course, and it’s only right for a player to find out why they’re not playing.“I knew myself that if I wasn’t performing well enough, I wasn’t going to be in the team, and that’s what happened.“The big thing with Jose was the communication with the players, and I know the players weren’t happy with him.”Rooney was then asked if Mourinho said anything to him about why he wasn’t being selected for games.“Nothing in detail,” the forward confirmed. “Not like ‘you’re not doing this, or not doing that’ - [which] would give you something to work on or to make yourself better at them certain things but I knew Zlatan was one of his big signings. Zlatan came in and was scoring goals, while I wasn’t playing at the level I knew I could do.“I knew that was the reason and that was what made my mind up to go and play elsewhere.”Watch Rooney's comments about Mourinho here...

Rooney’s honest comments about Mourinho’s poor man-management skills are telling and certainly explain why he lost the Old Trafford dressing room.

Not informing Rooney - one of the best players in United’s history - why he’d been dropped is unacceptable.

If he treated a club legend like that, just imagine how the rest of the players were dealt with after Rooney’s departure in 2017.

No wonder the players were reportedly relieved when it was confirmed earlier this week that the former Real Madrid and Chelsea boss had been sacked.