Prandelli is set to trim his provisional squad by revealing his final 23-man group on Sunday, and he claims that the approach against the Irish at Craven Cottage will be a factor in his decision.
"My choices will be based on the approach that we want to have on the pitch," Prandelli told reporters.
"It's the most difficult aspect of my job. I have seven strikers and I will have to drop two."
Italy will take on England, Uruguay and Costa Rica in Group D.