Juve - who knew a win or draw against Atletico Madrid on Tuesday would be enough to secure qualification for the last 16, regardless of other results - reached the knockout stages of Europe's premier club competition with a 0-0 draw.
They could have finished top of the pool with victory by two goals or more, but scoring one proved beyond Juve, who were unable to capitalise on their dominance.
Buffon - who made an excellent save to deny Atletico's Koke in the sixth minute, arguably the best chance of the match - told Sky Sport Italia: "If you finish top, you're still going to meet the strong clubs.
"If you're better than them on the pitch, then you win, it doesn't matter when you face them.
"Atletico Madrid are now a prestigious side among the top four or five in the world.
"Their journey in Europe in recent years confirms that and so does this season after a slightly shaky start.
"I think they'll be protagonists in the Liga and Champions League."
Buffon felt Juventus' qualification - given they lost two of their first three matches - deserved to be celebrated.
"I think at the end of the day, considering how it got complicated after three games, we did well to get it back on track and reached the final match knowing at least a point would be enough," he added.
"Considering the performances we put in throughout the round, I think we deserved to secure qualification one or two games ago."
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