Messi and Ronaldo are arguably the planet's top two players, but Di Stefano says that Brazil legend Pele in his prime was better than both.
"Messi and Cristiano Ronaldo are both great players with specific qualities, but Pele was better," said Di Stefano.
"Messi is the more technical player of the two. He's better inside the area, the way he handles the ball and dribbles. You can see that he enjoys himself playing.
"Cristiano has a better body and is physically very strong. He has pace, speed and [is] a player with courage. Plus he can finish with both legs."
Di Stefano won five European Cups during his 11 years at Madrid.