The Real Madrid striker's former Manchester United colleague claimed on BT Sport: "He used to do that in training, you know. I swear, crazy."
Rio Ferdinand says Cristiano Ronaldo deliberately volleyed in his equalising penalty in Real Madrid's Champions League victory over Paris Saint-Germain.
Cristiano's 45th-minute kick, his 100th goal in the competition for Real, cancelled out Adrien Rabiot's opener for PSG as the holders won 3-1 in Wednesday's last-16 first leg.
Ferdinand: "Cristiano used to do that in training"
Television replays showed the ball appearing to bounce slightly when he planted his left foot next to the spot, before firing past goalkeeper Alphonse Areola with his right.
And Ferdinand, who played with Cristiano at Manchester United, claimed on BT Sport that this was an intentional move by the 33-year-old - and that he had seen him practise it during their time together at Old Trafford.
"He used to do that in training, you know," Ferdinand insisted. "I swear, crazy."
Wouldn't count as illegal double-touch
As Cristiano only connected with the ball with his right foot, such a trick would not count as a double-touch and, as a result, would not be against the laws of the game.