Why Ruben Loftus-Cheek Is the Chelsea Player with Most to Prove in Pre-Season

Chelsea midfielder Ruben Loftus-Cheek is currently on international duty with the England under-21s at the European Championship.

It's not the daily orders of England U21 manager Gareth Southgate that will be ringing in his ears, however. No, it's the criticism from Jose Mourinho that was sent his way when Chelsea's players departed for their summer holidays.

The Chelsea boss was furious after Loftus-Cheek's efforts, or lack thereof, in his team's final post-season tour match against Sydney FC early in June.

"With Ruben, it’s one step back in terms of my relationship with him," slammed Mourinho, relayed by Sky Sports.

"If he doesn’t know what it is to play for me and Chelsea it’s one step back. He has to learn that at 19 you have to run three times more than the others, you have to play to your limits and not play like a superstar with the ball at your feet because this is not under-18s."

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Now, it's time Loftus-Cheek put the record straight, which he recently went someway toward doing.

Speaking at a press conference with England under-21s, Loftus-Cheek acknowledged Mourinho's criticism.

"Yes, I listened to what the manager said and I wasn’t at the level I need to do better, and I need to do better if I want to play for Chelsea," he conceded.

"For me that is a reminder that I have to work hard to get in the team."

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Regardless of what Loftus-Cheek achieves with the England under-21s this summer, the big test for his club career starts in pre-season.

It'll be his first opportunity to work with Mourinho again, and from the first training session, the 19-year-old must remind his manager why he was promoted from the junior ranks.

We're not talking in terms of it being make or break for Loftus-Cheek just yet, although this summer has a sense of things being for real this time.

Until now, he has been a player with potential, a player for the future.

Well, the future isn't years ahead anymore—it's now. Loftus-Cheek's time has arrived, and he must show he is capable of transferring his ability at junior level to the professional game.

That comes with behaving like a senior player and how Loftus-Cheek conducts himself on and off the pitch.

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Mourinho will be watching, and given what went down in Australia, the criticism is going to be increased significantly whenever Loftus-Cheek fails to raise his efforts.

That's where too many young players fail. Arriving at a club with Chelsea's stature, the notion is that the hard work is over, that they have made it.

As cliched as it sounds, however, the endeavour and graft is only just starting at that point.

Loftus-Cheek may well be a part of Mourinho's squad, but there is no guarantee he will play matches.

Chelsea are the Premier League champions, and Mourinho, being a manager who preaches loyalty among his players, will want to remain faithful to those who delivered him the title.

How can Loftus-Cheek convince Mourinho he should be given a place above any of them? Why shouldn't Mourinho strengthen his team with a marquee signing who comes with proven pedigree?

The answer isn't by cruising through post- and pre-season matches without putting in the effort, that's for sure.

Mourinho has already clearly laid out what the midfielder needs to do. Loftus-Cheek must "run three times more than the others [and] "play to his limits" and drop the superstar attitude.

It was a wake-up call for Loftus-Cheek. When Chelsea return to training in July, he needs to answer it.

So much more than Chelsea career rests on it too. Mourinho needs to be shown that Chelsea's youngsters are an asset and not just a commodity to be sold on to finance the first team.

As the first through the door on his watch, those hoping to follow him are looking to Loftus-Cheek to show the way, to set the precedent.

We know he's got the ability. Loftus-Cheek must now prove he has the character and desire.

Garry Hayes is Bleacher Report's lead Chelsea correspondent. All quotes were obtained firsthand unless otherwise noted. Follow him on Twitter @garryhayes