Cristiano Ronaldo Could Face Two-year Ban if He Left Juventus Stadium Before Full Time, Claims Cassano

Cristiano Ronaldo walked off the field and glared at Maurizio Sarri, muttering something undiscernible.

He then stormed down the tunnel.

It was the 55th minute of Juventus' match against AC Milan and Ronaldo had just been substituted for the second straight match after another disappointing performance.

His replacement, Paulo Dybala, went on to score the only goal, helping Juventus to a 1-0 victory on Sunday.

Italian media reported that Ronaldo wasn't around to congratulate Dybala or his teammates, having left the stadium shortly before the final whistle.

"I don't know," Sarri said when asked if that was true. "If it's true what you say then it's a problem for him to sort out with his own teammates."

If Ronaldo did leave the stadium, the Portuguese star can be in line for a two-year ban.

Former Milan and Roma striker Antonio Cassano in a recent interview revealed that he himself was involved in a similar situation, and was urged to return to the stadium.

"Did he leave before the end of the game? You can't do that because there is an anti-doping control," Cassano told Italian TV show Tiki-Taka.

"I had to go back to the stadium urgently to avoid a two-year ban," Cassano added.

As of writing this article, no evidence has come to light of claims made that Ronaldo did indeed leave the stadium or try to avoid being tested.

Sarri, who took over as coach at Juventus this season, insisted he was more than fine with Ronaldo's reaction toward him. In fact, he was glad about it.

"If he gets angry at being substituted after all he has won, I'm very happy about that because it means he still has his head fully in the game and he wants to help the team at all costs," Sarri said. "I like it when a player reacts a bit when he gets taken off. I would be much more worried if it was the opposite."

Sarri said Ronaldo has been bothered by a knee injury for nearly a month and is playing through the pain.

Ronaldo finished last season - his first in Italy - as Juve's top scorer with 28 goals in all competitions. He has six so far this season, two fewer than he had after the same number of matches last year.

Ronaldo's next matches will likely be for Portugal in European Championship qualifying matches against Lithuania and Luxembourg.

(With inputs from AP)