London: The QPR boss believes that their west London rivals would struggle to find a replacement for the England midfielder, who he coached during his time at West Ham.
Harry Redknapp has spoken of his admiration for Chelsea`s Frank Lampard, and feels the Champions League winners would be wrong to let him leave the club.
Redknapp`s struggling QPR travel to Stamford Bridge on Wednesday to face their London rivals, who earned a hard-fought victory over Everton thanks to a double from veteran midfielder Lampard.
The England international`s current deal with Chelsea expires in the summer, and with a new agreement yet to be reached, speculation regarding the 34-year-old`s future has been rife.
However, Redknapp - who managed Lampard, his nephew, during his time at West Ham - believes the Blues would be best served by agreeing terms on a new contract for the midfield talisman.
He told the Daily Mirror: "I personally think they would be making a big mistake in letting Frank go. I don`t think you`ll find anywhere a better attacking midfield player who will score more goals in the Premier League.
"I don`t think they can upgrade from Frank. He is an amazing goal-scoring midfielder, so I still think there is every chance that he will still be at Chelsea next year.
"I think the importance of age can be overstated. I`ve said many times he is the best trainer I have ever seen in football, without a doubt. I saw him as a 16, 17-year-old - when all the other kids had gone home, he would be practising every day. I`ve never seen anyone even come close to him.
"He`s still in great shape and has still got that desire. Frank just gets on with it. Every club needs players like that, but you can`t put it into people, they have to want to do it."