The UEFA Champions League holders visit the Emirates Stadium for a last 16 first leg fixture on Wednesday, hoping to take a step closer to becoming the first team team to retain the trophy in the modern era.
But Guardiola feels that his influential captain is a vital cog, and hopes he can inspire Bayern to another victory at the stadium where they won 3-1 on their way to the final last season.
"It would be impossible to be here without Lahm. He's one of our most important players," he said.
"I expect players with a good mentality to win the game. Arsenal will fight. They're not new to the competition
"You can't dominate Arsenal for 90 minutes, it's impossible. They have quality players.
"It's the most prestigious competition in the world. This will be a good test to see where our level is at.
"We accept Bayern are favourites, but I'm used to that.
"It's a game between two of Europe's biggest teams. We're here to win and play well, we'll have to.
"My target is to play better each week. Defending the title is difficult."
And goalkeeper Manuel Neuer is looking forward to coming up against a familiar face.
"It's special to play in England against international team-mates," he added. "Me and Mesut (Ozil) are from the same city and went to the same school."
