Romelu Lukaku's poor scoring record against Manchester United's main rivals is not a big concern ahead of Sunday's clash with Chelsea, Jose Mourinho has insisted.
United's £75million summer signing has scored 21 goals in all competitions this season - but failed to hit the net against the top eight teams in the Premier League.
Indeed, of the 85 league goals Lukaku scored for West Brom and Everton before moving to Old Trafford, only 15 of them came in 57 games against the big six clubs - United, Manchester City, Chelsea, Liverpool, Arsenal and Tottenham.