Jose Mourinho's third summer in charge at Manchester United looks set to be another busy one, with the Portuguese planning plenty of departures and arrivals.

One player who is almost guaranteed to leave the club is Zlatan Ibrahimovic, who hasn't been the same since returning from last April's ACL injury.

And then there's centre-back pair Chris Smalling and Phil Jones, who are both set to face the axe this summer following underwhelming careers at the Theatre of Dreams.

Signed by Sir Alex Ferguson as exciting youngsters in 2010 and 2011 respectively, Smalling and Jones have never reached their potential and, if anything, become error prone.

Paul Scholes summed up the general feeling towards the duo last month by saying they look nervous in possession and are "all over the place" against top opposition.

"United have looked very nervous," said Scholes. "Jones and Smalling, anything around them, they've been nervous.

"As soon as they play against quality, they're all over the place. This has been indicative of their last few weeks. Shoddy defending."

Smalling and Jones were highly rated when they joined United all those years ago but, for one reason or another, never lived up to the hype - so why is that?

Well, Nemanja Vidic believes it's because they didn't have an experienced mentor alongside them when they first broke into the United team, which sounds about right.

Vidic and Rio Ferdinand were both at the club when Smalling and Jones joined, but because they spent a lot of time out injured from 2011 onwards, they were unable to help as much.

"It didn't help them (Smalling and Jones) because they didn't have a more experienced player to pick their brain when they played," Vidic said, per ESPN.

"It's not just about playing together with an experienced player. To rise, he needs to be encouraged a bit and made to feel comfortable in his shoes.

"If Phil Jones is 24 and playing alongside someone who is 34, the player who is 34 years old is using his brain more than the 24-year-old.

"If you lose that belief and think: 'Should I be here, or here, or be here.' Then it's difficult to play.

"So that didn't help them. Even if they do something bad, you say: 'OK, he's 24 but where was I to help him?"

Vidic clearly feels partially responsible for the way Smalling and Jones' careers have panned out at United, but you can hardly help being injured.