Manchester United have reason to complain after Diafra Sakho allegedly headbutted debuting defender Luke Shaw during Saturday’s clash, as reported by the Daily Express.

The West Ham striker could therefore face a charge from the Football Association, should the incident be proven by the Old Trafford club.

Man Utd stormed into the lead against West Ham, but the Red Devils struggled to keep the Hammers at bay.

A moment of madness from Wayne Rooney, which saw him kick out at Stewart Downing and receive a straight red card, put them under even more pressure, with an offside flag the only thing denying West Ham a late equaliser.

Rooney is set to miss three games, and the same punishment could befall Sakho, if he is charged.

The FA await the report from referee Lee Mason before deciding what to do to Sakho.

Shaw apparently complained to assistant referee Andy Garratt about the incident, and was left with a black eye.

Speaking about the game, Shaw said: “We have actually had a lot of bad luck, especially with Wazza’s red card as I would say there was a handball before that but the referee didn’t stop play.