The Sun newspaper reported that Wenger adviced his players to ake their priority catching the top flight's top four and forget about FA Cup victory.
Arsenal is five points off fourth-placed Chelsea and 12 behind leaders United. That gap will stretch to 15 points if United win their game in hand at home to Fulham on Wednesday, Feb 18 night.
"United look untouchable at the moment because they are already a long way ahead and have this game against Fulham, which they will certainly win. That means they will be 15 points ahead of us and, for us to catch them, we would need them to lose five games," Wenger said.
"Let's say they lose one of those against Arsenal, we'd still need them to lose another four - and they haven't done that so far this season."
"Our basic target is always to get into the Champions League. Therefore, the Championship remains this club's priority," he added.