Rafael Benitez's short term contract at Stamford Bridge runs out in the summer and, with Mourinho seemingly approaching the exit door at Real Madrid, speculation has mounted that the Portuguese could return to west London in the summer.
Speaking at the handover of the Champions League trophy in London, Lampard said: "Jose's an absolutely fantastic manager, one of the legends of the Champions League. There's no doubt about his credentials, whether he comes to Chelsea or stays at Real Madrid or whatever club he goes to, I believe he will be successful."
Lampard's own future is also up in the air with the club seemingly reluctant to offer him a new deal when his current contract expires at the end of the season.
The 34-year-old played some of his best football during Mourinho's trophy-laden spell with Blues and, while Lampard was full of praise for his old boss, he refused to comment on speculation linking him with a return.
"It's not for me to talk about the decisions. I wouldn't want to undermine the current manager for the last eight or nine games by giving you a headline like that," he added.
"While there's a manager in place now, although we know what seems to be coming at the end of the season, I don't think it's right to speculate about who the manager will be next season.
"I'm not sure if it affects my decision. If a manager comes in who likes me.... I don't know."
Lampard has called on Chelsea to give their next manager a fair crack of the whip and hopes that he lasts "more than half a season".
He said: "Whatever the situation, it would be nice if a manager could come in and have a good crack at some consistency and stay in the job. We all understand we've had some interim managers and the fans and the club would probably be happier if we could get a manager who could stay for more than half a season, or for some period of time."
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