Redknapp heaped praise on his nephew, saying all players should adopt Lampard's ultra-professional attitude.
"I've said many times that Frank is the best trainer I have ever seen in football," Redknapp said.
"I've never seen anyone come close to him. He's out there morning and afternoon and used to go home and train at night. He did that as a 17-year-old.
"He got a pair of running spikes and was out there every day because he wasn't quick. His dad (Frank Snr) did the same.
"Every club needs players like that, but you can't put it into people. Some people do it for a day and then don't do it any more."