Jose Mourinho said after the Burnley match that he will prioritise the Europa League over the Premier League.
United, who face City in a crucial Manchester derby at the Etihad Stadium on Thursday, were rarely troubled.
Wayne Rooney admits injuries have held him back this season but denies he is frustrated with his place in Jose Mourinho's squad.
Jose Mourinho made wholesale changes from their Europa League win against Anderlecht and leave Burnley with a 2-0 victory.
Wayne Rooney scored one goal and was involved in the other as injury-hit Man United closed the gap on Manchester City with a 2-0 win at Burnley.
English Premier League: Paul Pogba (53') Burnley 0-2 Manchester United