Chelsea and Spurs face each other in their FA Cup semi-final on Saturday and Lampard has no doubt that one of the keys to the game will be stopping the effectiveness of the in-form Alli.
"He has developed into a number 10, playing behind the main striker, rather than being a number eight and a more traditional midfielder who likes getting forward," Lampard told the BBC.
"He is so clever with his movement and clinical with his finishing, so he had to be given that free rein.
"Alli is a highly intelligent player - the kind of number 10 we have been craving in England for years, and bemoaning the fact we have not got one. Now he has really arrived," said Lampard.
Alli has scored 16 goals in the Premier League this season and his struck up a great understanding with forward Harry Kane, who has 20 league goals so far.
Lampard, himself an attacking midfielder who struck 147 goals in 429 appearances for Chelsea, says that Alli's movement is the key to his effectiveness and something he learned to develop.
Read the full article on eurosport.co.uk: Alli is what England have been waiting for, says Lampard