JON Harley has been a cup winner with Chelsea.

But he knows even a team that is the best in England right now cannot afford to be off their guard against Burnley.

The 29-year-old left back was impressed by the way the Clarets twice came back to beat Watford in September, when he returned to Turf Moor with his current employers for the first time since leaving this summer.

And it is that kind of stubbornness which he feels could cause Chelsea problems when one of the form teams in the Championship pit their wits with the Premier League’s elite on Wednesday.

“I think Chelsea are going to be favourites, and rightly so with being the Premiership team and one of the biggest clubs in the world,” said Harley.

“But I don’t think they will have the easiest of games.

“Burnley are doing well this season and showed against us what a good team they are, to have that team spirit to keep bouncing back.

“If Burnley play as well as they have been doing, then an upset is possible. I think you would be silly to back against Chelsea though really.”

But, despite his claret and blue connections, you would expect a lifelong Blue to say that; especially one who counts Chelsea and England captain John Terry among his friends.

The two are graduates of the club’s youth system, and Harley admits he is proud of the heights his peer has reached.

“He’s done unbelievably well,” he said.

“He has a lot of talent, but it just shows what dedication and hard work can achieve.

“When we were younger, he was the hardest worker at training, and it’s paying off for him now.”

Although Maidstone-born Harley is just over a year Terry’s senior, their debuts were a matter of months apart.

It was a brief cameo for central defender Terry as he came on as a late substitute for Dan Petrescu in Chelsea’s 4-1 Worthington Cup win over Aston Villa in October 1998, while Harley played all but the last seven minutes of a 1-0 win over Derby towards the end of the previous season.

“It was a dream come true to get a professional contract. I’d been there since I was 11 years old and enjoyed being a part of the club, playing with all my heroes. But to start playing in the first team was something special,” he recalled.

“Gianluca Vialli gave me my debut, and the majority of my appearances whilst I was there.

“Then Claudio Ranieri came in after him, but I enjoyed my time a lot more working under Vialli because I played a lot more so felt more part of the squad.

“Both came from a similar background so they weren’t massively different. They wanted a fit team and a hard-working team.”

He added: “I remember my first game very clearly because we won 1-0 at Derby and I managed to set up the goal for Mark Hughes.

“He was an unbelievable player. Anyone that knows anything about football would appreciate what a good player he was. He was probably the best at holding the ball up that there’s ever been.

“The best player I played with though was Gianfranco Zola, and virtually every player who has played with him would say the same. Everything about him was unbelievable.

“He worked incredibly hard at his game; he was the first at training and the last one in.

“He was a great talent and had a lot of dedication about him.”

Harley played in the Premier League, League Cup and Champions League with Chelsea, and it was under Vialli’s leadership that he picked up an FA Cup winners medal in 2000, following a 1-0 win over Easton Villa in the last final to be played at the old Wembley Stadium.

“That was the highlight of my career. It’s the only silverware I managed to get my hands on,” he said.

“I didn’t get on in the final, but I’d played every minute of the rounds leading up to it so felt I’d earned my medal.

“Looking back now it was disappointing not be involved, but at the time I didn’t actually think I was going to make the bench, so to do that on the day was something in itself, even though I didn’t play, because I was still part of the squad and it was still a big thing for me.”

After beating Fulham, Burnley are hoping for big things against Chelsea to keep their Carling Cup dream alive.

“I keep in touch with a few of the lads and they are very upbeat at the moment,” Harley continued.

“All they’re talking about is Robbie’s pants! But if he gets a chance I’m sure they’ll be on view.

“It will be interesting to see what happens.”