Yokohama - Chelsea legend Frank Lampard said on Tuesday he won't be looking backwards as he takes on possibly the biggest challenge of his career: managing his former team.

Speaking in Japan where the Blues are playing two friendlies, Lampard said he was "very happy" with his squad but expects to work the team hard during the pre-season.

"For me the story is not to look backwards," said Lampard, whose return to his former club as head coach was confirmed earlier this month.

"I know the club very well, I know the players very well. I have my own way that I want to work with the players," he told reporters in Yokohama, where Chelsea will face Japan's Kawasaki Frontale on July 19.

Lampard acknowledged taking on leadership of the Blues will be a major undertaking, with Chelsea having lost their best player of recent times, Eden Hazard, to Real Madrid last month, and serving a two-window transfer ban that prevents him from making new signings.

But he said there was no reason to dwell on the ban.

"I think I inherited very good players. We cannot bring in any players we know that... But I'm very happy with the squad.

"My job now is to work hard in pre-season with them. I like my teams to play with a lot of energy and speed, with and without the ball, so I want to win it back as quickly as we can," he said.

Chelsea's new $72 million signing, Christian Pulisic, is listed as one of the team members visiting Japan, but it was not year clear when he will arrive.

Lampard declined to reveal the line-up for the two friendlies on Chelsea's calendar, which include a much-anticipated face-off against Barcelona on July 23.

American international Pulisic signed a five-and-a-half year contract with Chelsea in January but was immediately loaned back to Germany to finish the season at Borussia Dortmund.

Lampard won 13 trophies in 13 years and became Chelsea's all-time leading marksmen with 211 goals from midfield during a decorated playing career at Stamford Bridge.

But he has a lot to prove in his new role. The former England midfielder has just one season of managerial experience having led Derby County to the Championship play-off final in May, when they were beaten by Aston Villa.