Cristiano Ronaldo has been one of the most professional footballers of all time, but his recent actions have given David Meyler cause to question his professionalism.
Ronaldo has come under increasing scrutiny from supporters this season, particularly for his off-field outbursts such as refusing to come off the bench in the final minutes against Tottenham Hotspur, as well as leaving pre-season matches at half time.
However, as Portugal prepare to tackle the world in the World Cup in Qatar, an interview with their iconic striker and Piers Morgan has become the biggest story circulating around Manchester United.
Among other revelations revealed in the interview, Ronaldo discussed his lack of respect for Manchester United manager Erik Ten Hag, and bit back at those that called him unprofessional.
For former Republic of Ireland defender David Meyler, Ronaldo's professionalism was never in question, until recently.
Speaking on Football Saturday, Meyler explained why he felt that Erik Ten Hag's approach to managing Ronaldo has been a misstep.
"The biggest thing with Ronaldo is, I think Ten Hag is trying to coach the players," Meyler said. "I think Ronaldo can't be coached.
"He understands football, he is one of the best footballers of all time. He just wants to play. How did the other managers deal with him?
"Carlo Ancelotti is famous for being the best man manager. Then it went from Carlo to [Zinedine] Zidane, and Zidane obviously worked under Carlo, so he understands what makes Ronaldo tick.
"They know you don't need to coach Ronaldo. You need to just get him on the pitch."
The most professional footballer ever
Ronaldo is widely considered one of the greatest ever footballers. His goal-scoring rate, his ability with the ball and his professional lifestyle has all contributed to him being regarded as an absolute professional athlete.
"Ronaldo is probably the most professional footballer that has ever lived," Meyler said. "Everyone knows that. There's almost that part where he has to get that out there in the interview.
"You can see that it really bothers him, because he's been so professional for his entire career. At the same time, you don't get to the same level of Cristiano if you're not selfish.
"You have to look after number one, you have to do right by yourself. I imagine Ronaldo for a long time throughout his career was never worried about helping anyone.
"He was just focused on what he needs to do to get in the best condition to play on a Saturday."
Questions over his recent actions
However, while Meyler agrees that the Manchester United striker's historic professionalism is beyond question, his recent outburst as well as his protests against Ten Hag have caused him to question that professionalism.
"There's a lot of stuff thrown at him that I don't agree with people throwing at him," Meyler said. "There are certain parts that I fully agree.
"Don't get me wrong, the whole thing about refusing to come on, walking out the tunnel, that's bang out of order. That's totally unacceptable.
"Even the thing of leaving at half time in a pre-season game, he said there was eight players but because Ronaldo was one of them it was all made about him.
"He said in previous pre-seasons players had done the same thing, that was never an issue. He'd done it before.
"There's a lot of things that I'd like to know more about, but certainly some of his professionalism I would question, yes."
Football on Off The Ball brought to you by Sky. All the football you love in one place across Sky Sports, BT Sport & Premier Sports.