Manchester United boss Sir Alex Ferguson was bemused by the rash of bookings his team received during their 1-1 draw at Chelsea.

Ref Mike Riley booked seven United player.

The visitors were lucky the damage was not even worse given Cristiano Ronaldo got away with a blatant dive just after his introduction as a second-half substitute and Rio Ferdinand appeared to charge right into Didier Drogba as Riley blew for full-time.

As both Ronaldo and Ferdinand were among the seven offenders, United could easily have been cursing a red card as well as the glut of yellows which leaves them facing an automatic FA fine.

Yet Ferguson did not believe there had been a bad tackle in the game.

"The game is being screened worldwide," he reflected. "Everyone is watching it and something like that goes on.

"It was a competitive game but I did not think there was one bad tackle in it."

Apart from Ferdinand and Ronaldo, Paul Scholes, Dimitar Berbatov, Gary Neville, Wayne Rooney and Patrice Evra were cautioned.

"People are saying, 'What is going on here?' but it is difficult to say anything about the referee," added Ferguson. "I do not want to get involved."