The Spanish club, who were beaten on penalties by Real Madrid in last season's final, meet the Foxes in the quarter-finals of the 2016/17 edition of Europe's elite club competition.
Leicester got past Atleti's La Liga rivals Sevilla in the Round of 16 and Griezmann knows he and his teammates will have their work cut out for them on April 12 at the Vicente Calderon and April 18 at the King Power Stadium.
"If we want to reach the final like last year, we need to beat everyone," he said on a web chat for L'Equipe.
"Upfront they have pace with [Jamie] Vardy, [Riyad] Mahrez is a great player. At the back they're strong.
"It will be tough to get past them. I watched the match against Sevilla – from dead balls they can cause us damage."