The stakes will be high for Arsenal in the Group F match, given their 2-0 loss at Borussia Dortmund on matchday one.
Galatasaray fared slightly better, drawing 1-1 with Anderlecht, but would be expected to sit back at Arsenal.
Prandelli does not want his side to do that, though, and while he concedes Arsenal are likely to control possession, he wants the Turkish Super Lig outfit to attack their opponents.
"We believe that we have to be brave," Prandelli said.
"I believe we don't know what we can actually achieve. We can improve from today onwards.
"In our first match [against Anderlecht], we played very well. We played aggressively. Wednesday will be a different game.
"We are playing against a quality, experienced team at their ground. They will try to come into our half and hold the possession. We will try to play our own game."
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