Manchester United manager Jose Mourinho has blamed "crucial mistakes" made by referee Michael Oliver for his side's 3-1 defeat to Watford on Sunday afternoon.

The Red Devils fell to their third loss in the space of a week in all competitions after Etienne Capoue, Juan Zuniga and Troy Deeney found the net at Vicarage Road.

Mourinho, who suggested that poor officiating was behind United's 2-1 defeat to rivals Manchester City last weekend, has again hit out at the level of refereeing as he believes that Capoue's opener should not have stood due to a strong challenge by Miguel Britos on Anthony Martial in the build-up.

"I can split this into three factors - one is the referee's crucial mistakes, it's not in my control," he told reporters. "I can't do anything, I can't change that, it's not under my control.

"But against Man City you know what happened in the 55th minute. Today, you know what happened in the first goal, so we were punished by these mistakes but I can't do anything."

United will be looking to avoid a fourth defeat on the spin when they head to Northampton Town in the EFL Cup in midweek.