Derby have entered talks with Frank Lampard over an extension to his contract - although Chelsea are still expected to make a formal approach to hire him, Sky Sports News understands.

Lampard still has two years on his existing contract but Sky Sports News understands Derby had always planned to discuss a fresh long-term deal at the end of the season.

With no formal approach from Chelsea yet to discuss taking him to Stamford Bridge, Derby are pushing ahead with their plans to build a structure around him.

According to Sky sources, Chelsea regard Lampard as their top choice to replace Maurizio Sarri, who has reached an agreement to take over at Juventus.

Sky in Italy understand that, while Chelsea and Juventus have agreed the details of Sarri's move to Turin, he will not be confirmed until the Premier League club have finalised plans to bring in Lampard.

It is understood that there is a clause in Lampard's existing deal with Derby which allows him to move - although the Sky Bet Championship side will demand £4m in compensation.

While Lampard would find it impossible to turn Chelsea down if an offer is made to him, he is also very respectful of Derby's fans and the club's owner, Mel Morris, who gave him his first chance as a manager.

Frank Lampard guided Derby to the Sky Bet Championship final last season

Under the terms of his current deal, any club wishing to take him is required to pay £3.5m in compensation to Derby and that figure rises to £4m if the buying club is playing Champions League football, which Chelsea will be doing next season.

Lampard spent 13 years in west London, winning three Premier League titles, four FA Cups, two League Cups, the Europa League, and Champions League, becoming the club's all-time top goalscorer in the process.

Di Matteo: Lampard deserves a shot

0:31 Roberto Di Matteo says it is not too soon for Frank Lampard to become Chelsea manager because he has all the tools needed to succeed in the role. Roberto Di Matteo says it is not too soon for Frank Lampard to become Chelsea manager because he has all the tools needed to succeed in the role.

Former Chelsea midfielder and manager Roberto Di Matteo says Lampard is "definitely the right man" to step into Sarri's role.

The Italian also dismissed suggestions that it is too early for him to take such a high profile role.

"He's definitely the right man, he's got personality," Di Matteo told Sky Sports News.

"I followed Derby last season and he plays very good football - he has all the experience in the world.

"It's a great fit, whether it's right now or not? Only time can tell. You can't say it's too early, you have to give people a chance.

"He's got all the tools and it will make a lot of people happy if he is the next manager."