Wayne Rooney was accused of elbowing Wigan midfielder James McCarthy after Manchester United went four points clear at the top of the Premier League with a 4-0 win at the DW Stadium.

Angry Wigan manager Roberto Martinez insisted United's England striker should have been sent off after the first half incident on Saturday.

The game was goalless when Rooney clashed with McCarthy, but United eventually ran out easy winner with Rooney scoring the killer third goal.

Rooney caught McCarthy in the face with his elbow during the opening minutes, but referee Mark Clattenburg took no action apart from awarding the host a free-kick.

Martinez felt Rooney's elbow was part of a plan by United to intimidate McCarthy.

"I felt Wayne Rooney was very fortunate. It was clearly a red card," Martinez said. "I saw the incident clearly and the referee did as well because he gave the free-kick.

"Once you give a free-kick it is quite clear that it is a red card. When you look at the replay, it is quite clear he catches James McCarthy in the face with his elbow.

"Manchester United was trying to impose itself on James McCarthy and stop him from playing.

"If one of my players had done that, I would think he was very lucky to stay on the pitch.

"It is a big call in the game. It is unfortunate because the referee saw it but he didn't feel it was a red card."

However, United manager Sir Alex Ferguson felt Clattenburg was right not to punish Rooney.

"I have had a chance to see it. There is nothing in it," Ferguson said. "Mark Clattenburg saw it. I think he said it was an accident.

"But, what will happen, the question has been asked and because it is Wayne Rooney the press will raise a campaign to get him hung by Tuesday or electrocuted or something like that.

"It is unbelievable. Watch the press. It will be interesting to see it."

Despite the controversy, United travels to reigning champions Chelsea on Tuesday knowing that victory at Stamford Bridge will leave it seven points clear of Arsenal at the top of the table.

The United overcame a labored first half performance to win comfortably thanks to two goals from Javier Hernandez, one from Rooney and Fabio Da Silva's late effort.

But veteran keeper Edwin van der Sar still had to produce a vintage display to deny Wigan's Victor Moses, Ben Watson and Maynor Figueroa.