Ronaldo and Rooney spent five years together in Manchester United where they won the Champions League and three Premier League titles.
And Ronaldo was asked about Rooney before his showdown with Manchester United this week.
Ronaldo has been in good shape for Juventus this term since his £ 105m move from Real Madrid.
But when asked about his former teammate he was free and opened the nickname he gave him.
"To me, the power of Wayne Rooney is his mentality and strength," Ronaldo told Goalhanger movies.
"He never ends, he always runs, helps the team. He is a great team player and he makes goals. He made important goals, for me he is fantastic.
"He was the kid in England. Everyone loved him. He's a fantastic boy, amazing player.
"I used to call him, between me and my friends, the pit bullet. I remember when he dropped the ball, he was so powerful, a strong guy, he's shooting incredibly."
But he was happy to watch his time at Old Trafford and also revealed he could go with Rooney again one day.
Ronaldo added: "He made many goals, what can I say? I miss playing with him." The future knows nobody. Maybe we'll play again one day. "
Rooney moved to America earlier this year to play MLS football with DC United.
He helped the Washington side to reach the play-offs where they lost Columbus Crew on punishment.
Rooney will return for England once in friendship with the United States.
The 33-year-old 53-year-old England defender will win a 120's in comeback appearance on November 15 – two years after his last international match against Scotland in November 2016.
"I'm really humble and very excited to play for England at Wembley again," said Rooney in a statement from FA.
"I would like to thank Gareth Southgate and FA to invite me back and help support my foundation in the process.
"Playing for England was the greatest honor of my career – winning my 120th and last cap is a special special moment for me. It's a match that the match will be against the United States and I hope both sets of fans enjoy game."
After making his international debut in 2003 as England's youngest ever player, Rooney Bobby exceeded Charlton as the country's leading score in 2015.
Over a 13-year international career, Rooney England represented at three world cups and three European championships.
Rooney, who started his career in Everton, spent 13 seasons at Manchester United.
After a season back in Everton, he moved to the United States to join D.C. United – which he helped in the playoffs in his first campaign.
He is not expected to start or hijack the side against the United States, but will be set as a replacement for a charity campaign arranged to raise funds for the Rooney Foundation, which aims to improve the lives of disadvantaged children.
England also plays Croatia at Wembley in the Nations League on November 18th.