Alexander-Arnold will pit his wits against the Portuguese talisman when Liverpool lock horns with Real Madrid in the Champions League final on May 26.
The 19-year-old has enjoyed a meteoric rise with the Reds this season and after coming on as a last-minute substitute of the opening day of the Premier League campaign in a 3-3, has been an ever-present feature of Jurgen Klopp’s back four.
The left-back could also be included in Gareth Southgate’s 23-man squad to go to the World Cup in Russia next month.
And Arnold has revealed he had a lot of admiration for Ronaldo when he was younger, but that was put to one side when he played for United.
“I suppose [I was a fan, but] not when he was playing for Manchester United though,” Arnold said.
“You have to admit he’s an unbelievable player and he’s done exceptional things in the game.
“The numbers that he does season in, season out are absolutely unbelievable.
“Come May 26 we’ll be looking to stop him and the rest of Real Madrid.
“Obviously the thing is, Real Madrid are a very strong team, so no matter who you’re going to play against it’s going to be one of the best players in the world because that’s the nature of the team they have.”
Arnold also admitted he’s been studying Ronaldo a lot by watching YouTube clips, adding: “With Ronaldo being one of the greats, probably one of the best players ever, it’s going to be an honour to hopefully play against him.
“You know a lot about him and the likes of Messi because you watch them on YouTube when you’re growing up. You always watch those type of players.
“But you’ve just got to focus on the game and if he’s a direct opponent you have to see what the strengths and weaknesses are and use them to your advantage.”
Liverpool finished their league campaign on Sunday with a 4-0 win over Brighton to secure a top-four finish.