Manchester United midfielder Cristiano Ronaldo has raised yet more issues with the standard of refereeing in the Premier League by questioning Howard Webb's decision to book him for diving in yesterdays match against Blackburn Rovers but failing to book Morten Gamst Pedersen for the same offence.

The Portuguese winger was booked for a blatant dive just outside the penalty area in yesterdays Premier League fixture, but Webb did not hand out the same treatment for Pedersen when he looked to have been brought down by United full-back Rafael Da Silva.

The referee did not give a penalty, but did not book Pedersen for simulation either.

Ronaldo is quoted by football365.com as saying, "I didn't think their's was a penalty.

"The referee did not give it anyway. He didn't give the player anything either - but he gave me a yellow."

Rovers boss Sam Allardyce felt that Pedersen had not dived and that Rafael had tugged the Norwegian winger.

"It is not a blatant one, but Da Silva has had a little tug," argued Allardyce.

"You have to make the referee's mind up - Kevin Davies will tell you that.

"He gets fouled more than anyone else in the Premier League. He stays on his feet and never gets fouls. What do you do?"

Ronaldo may have been sent off earlier in the game for kicking out at Rovers midfielder David Dunn, an offence that went completely unpunished by the referee.

Sir Alex Ferguson feels the referee made the right decision not to send off Ronaldo.

"I know people will make a meal of it. But it was no more than a flick, and the referee gave him a warning. You see it time and time again," said Ferguson.

"He has to live with the examination of him. It would have been a ridiculous sending-off."