"There should be a level of respect shown between the clubs, but we can't do anything about the speculation. All we can do is look after our own situation," said Neville.
"Cristiano is our player and he will continue to be our player as long as we want to keep him. The manager has already said that.
"Manchester United don't let players go that they don't want to sell, it's as simple as that. And they want to keep Ronaldo," he added on the club website.
Ferguson lashed out at Real Madrid on Thursday as new rumours swirled about a Ronaldo move to the Bernabeu at the end of the season, saying he would not "sell them a virus."
Real Madrid president Ramon Calderon, who like Ferguson is in Japan, termed the comments "sad."
"In the code of conduct of our club, there is no room for insults, for scorn nor for a lack of respect for our rivals. Perhaps for this reason, Real Madrid is respected in all corners of the world," Calderon said in a statement.
"It is sad that a professional with the career of Mr. Ferguson can make a statement like that, which is in addition to other unfortunate statements made in recent months.
"Despite these, Real Madrid will never respond without respect to Manchester United, to any of its officials, nor of course to its supporters."
Calderon also confirmed that there was "no agreement" between the two clubs on a Ronaldo transfer, as alleged by Spanish media.
Ronaldo was touted all summer as an 80 million euro (115 million dollars, 74 million pounds) Real target, with United furious at the Spaniards' constant efforts to prise him away from Manchester.