The two sides clash in one of the most eagerly anticipated Champions League final for years on Wednesday, with the battle between Ronaldo and Lionel Messi set to take centre stage.
In a press conference this evening though, Puyol acknowledged that United have a lot of other talented players aside from the Portuguese star.
"Of course we know what Ronaldo and Manchester United can do," explained the defender.
"They have excellent players both in defence and attack, they are a very strong side. Sure attackers can make the difference, but you can never know who will turn the game just like in Paris three years ago."
On that occasion in France it was a defender who won the match for Barcelona as they picked up their second Champions League trophy.
This Wednesday they can secure an historic treble with a victory, and Puyol is raring to get out onto the pitch and play.
"It's hard to get to the Champions League final so you have to enjoy it, I can't wait for the final and to get it started. I have a very good feeling indeed, we have a great team in front of us
and we have had a good season and we will try to win the final," he said.
"If we can repeat the result from the 2006 final that will be just fine, it will be a complicated match, we have a strong team, we are good in defence and we have some great players, but we will have to do a lot of work to win.
"It is going to be a hotly disputed final and it will be against one of the best teams in the world and hopefully we will prevail."
James Walker-Roberts, Goal.com