Wednesday's match at the Santiago Bernabeu will see the Portuguese face his former club as the two giants meet for the first time since an enthralling 6-5 aggregate Champions League quarterfinal win for Madrid in 2003. Madrid will pay a return visit to Old Trafford for the final leg on March 5.
"The fans appreciated him when he was here and since he's been gone they sing his name. He came here a young boy and left a world-class player," Ferdinand told UEFA's official website. "He showed a lot of respect when he left and still does."
Ferdinand stated that while he had previously kept in contact with Ronaldo, who won three successive Premier Leagues and a Champions League at Old Trafford, this would stop in the run up to the match.
"We've had a few texts, but when you get into a situation like this when you're coming up against a friend, all the texts and the conversations go to one side and you don't really speak until you actually get the game over and done with," Ferdinand said.
Ferdinand also recalled the 2003 defeat to Madrid, in which a 4-3 win in the second leg at Old Trafford was not enough to overturn a 3-1 deficit.
"In the away game – they really played us off the park if I'm honest," Ferdinand stated. "Raul was just difficult to get up against. In terms of making you think, he definitely was the most intelligent player I've played against."
The Red Devils failed to get past the group stage last year, and the year before saw a disappointing 3-1 defeat to Barcelona in the 2011 Champions League final at Wembley, the same venue for the climax of this year's competition.
"It'd be nice to go back there and put what happened last time right," Ferdinand said. "We went there and we didn't give a great account of ourselves. Lionel Messi, in the two Champions League finals we played against him, was the main difference really."