Can you name the tennis player who famoulsy yelled "You cannot be serious!" at an umpire?

The answer to this is John McEnroe. He is now a retired tennis player but he is still well-known for his days as one of the greatest tennis players of all time. He is also popular for his angry outbursts in court. It seems that he is very confrontational especially when he believes that he is in the right.

He got into trouble not only with the umpires but also the other tennis officials. He has won a total of 881 times which is pretty good considering how other tennis players fare. There are a lot of people who consider him their inspiration even if he was hot-headed and he often said what was on his mind. He is still known for the remarks that he makes at present time.