Claudio Marchisio struck Juve's winner and Ranieri remarked: "We knew Fiorentina were going through a tough time and had already won here last season, so they were fired up and would give us real problems.
"We struggled right to the end and Fiorentina play very good football. It's fair to say the only thing they were missing was a goal.
"We do struggle against teams with this system and have to tighten up the lines. We didn't always manage it."
Alessandro del Piero created Marchisio's winner and Ranieri added: "Del Piero's pass was wonderful. We were under a lot of pressure at that time and I needed another pair of fresh legs who could get past his man and cause problems for the Fiorentina defence. With all the trouble we have in the treatment room, I had no other choice.
"There is no ego in this squad. It's only natural that everyone wants to play and after a few minutes of cooling down, he understands that the Coach has to make certain decisions.
"Marchionni and Marchisio put in excellent performances. They always give their all and carry the cart for the whole team, so they are crucial.
"In the first half the midfielders could not find their positions, as they had to defend and then straight away counter, so it was tricky for them."