Ronaldo makes his first return on Tuesday since his departure in 2009 for the second leg of Real's last-16 tie against old club Manchester United.
The Portuguese star is expected to be afforded a warm welcome from the United faithful, with Patrice Evra revealing last week that Ronaldo had told him it would be difficult for him to return to his old stomping ground.
However, Alonso believes Ronaldo will cope with the atmosphere and focus on doing his best for Real.
"I don't think so," said Alonso when asked if emotion might get the better of Ronaldo on Tuesday night. "He's really looking forward to the game.
"Before the game I think he'll get a great reception but once kick-off starts, he'll just be thinking about doing the best for our team. Hopefully it will be a great night for him.
"It's very different to play with Cristiano than against him. I've played against him and with him, and I'm lucky enough to say he's on my side and I'm pleased to have him on my side.
"He's in terrific form and he's looking forward to it. In his mind is just to play a good game and to get through this stage."
Alonso claims the game is not just about Ronaldo and that there are other players on both sides who could decide the outcome of the tie.
"We'll have more chances to win if Cristiano plays to his best, but if we don't defend well then United will have chances to win," added Alonso.
"It's not just about Cristiano, other players can have a really important impact on the game."
Alonso is not worried about the reception he might face due to his Liverpool connections and insists all the focus will be on what is an eagerly anticipated encounter between two European titans.
"I spent five years playing in England with Liverpool and there was a special rivalry," continued Alonso.
"But you don't really need to add anything to this match. Everyone will be glued to the television watching it, wherever they are."