The Irish pundit says the Spurs man isn't all that just yet.
The 20-year-old midfielder scored 10 Premier League goals and set up 12 in all competitions en route to winning PFA Young Player of the Year following a brilliant first season with Spurs.
Indeed, Alli is widely believed to be one of the most promising young talents not only in England, but in the whole of Europe at the moment.
That being said, the outspoken Irish pundit is not sold on the youngster's talent just yet, suggesting he has a lot to do before he justifies the hype surrouding him.
"I think he's overrated, Dele Alli, but he has scored some sensational goals for Spurs," Dunphy said to RTE Sport before England's Euro 2016 clash with Wales.
"But if you look at his play over 90 minutes - he gives the ball away a lot and makes a lot of daft runs."
Alli is a fine talent and, at 20, he is surely going to improve a lot in the coming years.
However, one thing which could, and probably will, hold him back is his temperament. Classy player, but his hot-headed nature is a weakness and one which will undoubtedly be exploited by opposition players in years to come if he does not get a handle on it.