After everything that they have lived through, the parting was always going to be sorrowful and yet for José Mourinho there was still the sprinkling of sweetness. Frank Lampard, the Chelsea manager said, had not really said farewell upon the end of his 13-year playing career at the club because he most assuredly would be back.

Nobody knows precisely when or how but the owner, Roman Abramovich, has decreed it. Whenever Lampard is ready to return to Chelsea in a non-playing capacity, he will be granted the privilege of hand-picking his role. Mourinho even said that Lampard could become his assistant manager.

“You can’t imagine how difficult it was,” Mourinho said of the face-to-face meeting with Lampard, when it was agreed the England midfielder’s Stamford Bridge contract would be allowed to expire at the end of June. “But at the same time, I can feel some happiness about the process because, for sure, he comes back to Chelsea. Mr Abramovich – the No1, the most important person – wants very much for Frank to be back, I want him to be back, the staff want him to be back, so he comes back, for sure.

“The other thing is that he can come back the way he wants. Mr Abramovich has left the door completely open for him on the understanding Frank can do anything he wants at this club. He can come back when he wants and, to repeat Mr Abramovich’s words, the way he wants.

“He can be a coach, he can start at the academy, he can start being my assistant at the same time because he is doing his coaching badges or he can start in a different role. He can decide: ‘I don’t want to start immediately at the coaching role, I want to be an ambassador, I want to work hand in hand with the CEO, representing the club in important places of our life.’ It’s not the end of Frank Lampard’s career in Chelsea. It’s just a little break.”

Lampard is 35 and believes he is fit enough to play on for “a few more years”. If it were his choice he would surely have preferred to continue at Chelsea, where he scored a club record 211 goals in 648 appearances and won three Premier League titles, four FA Cups, two League Cups, one Champions League and one Europa League. He started in nine of the club’s 12 Champions League ties this past season, including the semi-final, first leg at Atlético Madrid; he missed the second leg through suspension. And yet there was still the feeling he was no longer a first-choice selection. He started in only 20 of Chelsea’s Premier League matches.

“He’s a man to play a major role in a team, not like [what] happened in the last year – playing sometimes, sometimes not playing, playing 60 minutes, not starting every game,” Mourinho said. “I think for him, for his mentality, for his personality, it’s better to get a club and probably a competition where he is really the top man.”

Lampard has admitted he is considering an offer from New York City, the new Major League Soccer franchise that will launch in March 2015, although, if he accepts, it will most likely mean he will need a short-term contract for the first half of the next European season. Harry Redknapp, his uncle, would gladly take him at QPR.

Lampard, though, whom Mourinho describes as the “best No8 in the last decade”, is focused on the World Cup finals in Brazil, on adding to his 104 caps and helping the England squad on and off the field.

“I think the World Cup is the perfect way for somebody with more than 100 caps to finish his career in the national team,” Mourinho said. “I told him that: ‘Don’t go more than the World Cup. The World Cup is the right moment to finish.’ Does he accept that? Yes.”

José Mourinho is an exclusive analyst for Yahoo’s football coverage. Read his opinions at www.yahoo.co.uk/worldcup