The Portuguese superstar made his way from the Spanish capital to Turin over the summer, with the Bianconeri able to lure a talismanic presence away from the Santiago Bernabeu.
It has been suggested that further deals may be in the pipeline, with a number of Blancos players prepared to follow a former team-mate to Italy.
Ronaldo feels Juve already boast enough quality to ensure that those deals are not needed, but he can see why a Brazilian left-back may be added to the fold.
The five-time Ballon d’Or winner told Gazzetta dello Sport of the transfer rumours: “I see you write about James, Bale, Asensio but if I'm honest, Juventus do not need other players.
“You must talk to the president. On the future, I do not know.
“Marcelo is strong, we open the doors to good players and Marcelo is one of them.”
It may be that Ronaldo is offered a reunion with Marcelo and Co. in this season’s Champions League, before any possible recruitment options are explored.
The 33-year-old has captured that European crown in each of the last three campaigns, and five times in his career to date.
He is determined to deliver another success for Juve and claims he would have no problem disposing of Real along the way were his path to cross with a club he retains strong ties to.
Ronaldo said: “For me it is the same. The past has passed, now I want to win for Juventus.
“I have to defend these colours and the rest does not matter.
“If I played against Real, I would try to give my best.”
Ronaldo has already faced one set of former employers in continental competition this season, with an away win and home defeat taken in against Premier League heavyweights Manchester United.