Capello, who spent the 2006-07 season in Spain, said earlier in the week that Ronaldo was a great player, but also a "negative group leader" at Madrid.
"We sold him in January and the atmosphere within the group changed completely," the 69-year-old said at the Globe Soccer Awards.
However, speaking to Folha de S.Paulo, Ronaldo responded to the Italian's claims.
"Capello was a great trainer in his time, around the 1990s. When he came to Real Madrid he was already finishing and didn't motivate the players," he said.
"Proof is that after [Madrid] he never returned to manage a club."
