Fabregas, who scored the equaliser against the Azzurri in their cagey Group opener, was wary of the threat posed by the 33-year old Juventus midfielder while he was impressed by Mario Balotelli's performance against Germany.
"We will have to stop Italy's attackers and Pirlo as well," Fabregas was quoted as saying in Goal.com.
"Balotelli is a great player and he showed it yesterday. He scored two great goals against Germany in the semi-finals.
"That says it all. I really liked the way he played. He will be a threat, like Antonio Cassano or any other player, he said.
Meanwhile, Spain's influencial defender Sergio Ramos, who emulated Pirlo's chip in the penalty shoot-out against Portugal, praised the Juventus midfielder and labelled him as the 'reference point'.
"It could be beneficial for us to have already played them but they may change strategy. They are very quick and dangerous on the break and Pirlo is unique. With a single pass he can open you up and leave a man one on one. He's the player that makes the difference. We know Italy are a great opponent, quick and good in possession," a leading Daily quoted Ramos, as saying.
Pirlo's defence-splitting pass found Antonio Di Natale, who slotted home Italy's opening goal against Spain in their Group C clash which ended 1-1. But Ramos feels Pirlo is not the only threat to Spain.
Pirlo is their reference point. He dominates the game and controls the match. In that sense it's similar to the way that Xavi [Hernandez] controls the game. But it would be a mistake not to evaluate the rest of the other players," he said.