Real Madrid forward Ronaldo, who knows Old Trafford well from his time with Manchester United, is the current holder of the world's best player award.
Tuesday's match is set to see him face Barcelona's Messi, last year's runner-up, in international rather than La Liga action.
Inevitably, the pair have been the focus of attention in the build-up to the game and Monaco defender Carvalho told a news conference on Monday: “It is normal about the game to speak about Cristiano and Messi but I think it is Portugal against Argentina.
“For us Portuguese, everyone is expecting that Cristiano can win his third Golden Ball (Ballon D'Or).
“I am a little bit suspect (biased) but I think he is the best.
“We are so proud of him. He is doing a great job during this past six or seven years. He is improving all the small details, making so many goals.”