Cristiano Ronaldo departed the Juventus Stadium before the final whistle blew after being irritated by Maurizio Sarri‘s decision to take him off against AC Milan.

The Portuguese forward was taken off in the 55th minute of the game and appeared to mutter something in the direction of Sarri as he came off, visibly aggrieved by the decision.

Sarri suggested that an ongoing knee issue is responsible for the substitutions, and that the club “must thank” Ronaldo for battling through it.

“We must thank Ronaldo, because he made a sacrifice to be there at all tonight in a difficult situation. He did everything possible to play, but I saw he was not well and thought it best to take him off,” Sarri told Sky Sport Italia.

“It’s only natural a player is going to be irritated to leave the pitch, especially when he worked so hard to be there. Over the last month, he has had this little knee problem, he had a knock in training and it hurt the collateral ligament. When he trains at high intensity or plays, it unbalances him, so he ends up overcompensating and it damages the calf and thigh muscles.

“It is affecting his performances and he is not at his best at the moment. All players who are trying to give their best will have at least five minutes of being annoyed when they are substituted, but a coach would in general be much more worried if he didn’t seem upset.”

Ronaldo’s replacement Paulo Dybala scored the winner as Juventus moved back to the top of the Serie A table.

Inter Milan‘s win over Helllas Verona had taken them briefly ahead of the defending champions, but a fine goal from Dybala ensured Juventus secured a 1-0 win.