The defending European champs are yet not guaranteed progress to the knockout round and cannot afford defeat to Samuel Eto'o's Inter.
Puyol said: "We have no doubts. We know what we need to do, ie, what led us to win it all last season. We'll come with the same desire and ambition. The results sometimes do not always arrive, but we know that Barca-Inter is a final and will face it as such."
Asked about the potential absence of Lionel Messi due to injury, Puyol added: "Look, with or without Leo, there can be no doubts about this team."
On signing his new contract last month, Puyol admitted: "Yes, I thought about leaving. At the beginning of the season I asked for time to get things clear. After that time I concluded that there is nowhere else like here."