Cristiano Ronaldo is likely to end his first season at Juventus with a Serie A winners’ medal.The Old Lady currently sit 16 points clear of second-placed Napoli at the top of the table - a lead that was extended thanks to a 2-1 victory at the Stadio San Paolo on Sunday night.Miralem Pjanic and Emre Can put Juve 2-0 ahead at the break before Jose Callejon set up a tense final half-hour by pulling a goal back.However, Callejon’s goal proved little more than a consolation, leaving Juve with one hand on the Scudetto.Ronaldo is frustrated any time he finishes a match without scoring and Sunday’s tie in Naples was no exception.Sampdoria’s Fabio Quagliarella now sits alongside Ronaldo on 19 goals in the top scorer charts after his brace against SPAL, which would only have added to the Portuguese legend’s frustration.Ronaldo has now gone three games without scoring after also failing to find the net against Atletico Madrid and Bologna.Footage has emerged from the Napoli match showing Ronaldo’s exasperation with his teammates’ lack of pressing over the course of the 90 minutes.There were several moments where the 34-year-old clearly felt his teammates weren’t working hard enough to either win or retain possession.Ronaldo, almost acting as Juve’s coach on the pitch, had to constantly tell his fellow players to press and push up.And at one point, angry with his teammates’ lack of support, he apparently shouted “Mister!” - a term commonly used on the continent, like ‘gaffer’ in England - towards Massimiliano Allegri.Watch the minute-long video here...

He clearly felt his manager wasn’t doing enough in that moment, either.

"It was was a crazy match with various incidents that made it pretty messy. The two best teams in the league were facing each other,” Allegri was quoted as saying by the Mirror after the match.

"Napoli have great technical skills and made it really difficult for us.

"As long as the maths don't give us the title, we have to keep winning our games.

"I think we need at least five victories to claim the Scudetto. We won our two matches against them [Napoli].

"Now we have to think about beating Udinese, which will be very important going into the match against Atletico [Madrid in the Champions League]."