Cagliari president Tommaso Giulini insists Cristiano Ronaldo should've been sent off in defeat to Juventus.

Ronaldo hit a hat-trick in Juve's 3-1 win, but at 1-0 Ronaldo clashed with Cagliari goalkeeper Alessio Cragno with a high boot.

“We didn't put in a good first half, as we lacked ferocity, aggression and heart," Giulini told Sky Italia.

“I hope to see a completely different attitude when we play Spezia next week. We didn't even get a single yellow card and I think that reflects how timid our performance was.

“I am truly disappointed by the way my players approached this, but I am above all upset that Ronaldo was not sent off, as that incident could've changed the game.

“It was dangerous play, it put the safety of our goalkeeper at risk and therefore ought to be punished with a red card. This is what the rulebook states."