LONDON (Reuters) - Inter Milan coach Jose Mourinho has said Chelsea midfielder Frank Lampard was the best professional he had worked with in his coaching career.

"Frank Lampard is a different kind of person, not so extroverted. He is the best professional I have ever worked with," Mourinho said in an interview on www.feelfootball.com.

"He's the player that trains better, has more concentration, more commitment and is always focused on himself."

New Inter coach Mourinho is keen to link up again with Lampard having won two Premier League titles with the 30-year-old while in charge at Chelsea.

However, the west London club said this week they would not enter into negotiations with the Serie A champions over the England player, who has a year left on his contract.

"He is never happy about his performance, always wants to improve, always wants to learn," said Mourinho in the interview recorded in May but only approved for release by him this week.

"If he makes a mistake in a game, the next day in training he wants to stay one more hour to practise exactly that situation.

"I remember he missed a goal once with a difficult left-foot volley and the next day in training he was there one hour after the training session practising that volley with the left foot.

"Lampard is incredibly professional. God gave players the talent... but some of them waste this talent but some of them with this kind of mentality make themselves better and these are the kind of the players that can last forever."

(Writing by Ken Ferris, editing by Justin Palmer)