The striker demanded an improvement from his team after they almost threw away a two-goal lead against Watford on Saturday
Romelu Lukaku admits Manchester United were lucky to get away with a "sloppy" second half as they edged past Watford 2-1 at Vicarage Road on Saturday.
United were two goals to the good at half-time thanks to Lukaku's opener and Chris Smalling's resounding second, but allowed Watford back into the game after the interval.
Andre Gray set up a tense finish with a goal in the 65th minute, but Jose Mourinho's side held firm to record a second consecutive Premier League win.