Ross Barkley got off to a shaky start to his Chelsea career last week, though after such a long lay-off it is quite understandable.

The former Everton man completed a £15m move to Stamford Bridge earlier in the month, having rejected a deal which would've seen his boyhood club pocket £35m back in August.

Barkley was entering the final six months of his contract at Goodison Park, and his reluctance to sign a new one left the Toffees in an impossible position, allowing Chelsea to get a bargain for a player of his ability.

At just 24 years old, the best of his career should still be ahead of the England international, though he's already suffered some serious injuries.

Barkley had a double leg-break while playing for England under-19s in 2010, suffered a ligament injury in 2014, and recently had surgery after he ruptured his hamstring.

He didn't play for almost eight months until he came on as a first-half substitute for the injured Willian at the Emirates last week, but was unable to make a big impression.

And the Liverpool-born midfielder infuriated Chelsea fans when his last-minute corner failed to beat the first man, costing them a final chance to take the Carabao Cup semi-final with Arsenal to extra-time.

He then made a late cameo in the 3-0 win against Newcastle in the FA Cup on Sunday, but was barely given enough time to impact the match.

The Blues' manager Antonio Conte made a rather bizarre comment about Barkley after the Arsenal tie, saying: "When there is an injury to one of your best players it is not simple, especially when on the bench the only substitute is Ross Barkley."

That can't have filled him with confidence, and the Italian has now revealed he has a "worry" about his new midfielder after watching him play.

He claims there is no guarantee that Barkley will adapt into Chelsea's style of play, and that he needs time to try to fit in, though he was pleasantly surprised by his physical condition.

"I thought I’d find a player who was not in good physical condition. Instead, I was surprised to find a player in good physical condition," he started.

"My worry is not about his physical condition, but only to go into our idea of football, to understand the movement without the ball and with the ball.

"For this, he needs a bit of period to go into our idea of football. To understand this. My worry is not about his physical condition, but to get into our idea of football."

Conte however does think there is still time for Barkley to make England's World Cup squad this summer, but can't give him any guarantees about a spot in his starting line-up.

He pointed out that the 24-year-old is competing with great players at both club and international level, and that he must make the most of every opportunity he is given.

"In every game when you decide to play for a great team, in every game you are in contention with other players.

"You have to try and exploit every chance you have to play and show you deserve to play.

"The time is right to find a place in the World Cup (squad), but for sure it won’t be easy because, in the England squad, they are very strong."

Having played at the 2014 tournament, it would mark a regression for such a young player to miss out on the next squad.

But unless he is able to put in some eye-catching performances in the little time he has to prove himself, it looks as though Barkley will not be travelling to Russia this summer.