Manchester United boss Ole Gunnar Solskjaer has demanded more from his attacking players after the win over Partizan Belgrade.
United got back to winning ways with a 1-0 victory in the Europa League clash, courtesy of Anthony Martial's penalty.
"Second half I thought we dug in really well in the box, defended really well in the box. They played well in the second half and made us defend too deep," Solskjaer told MUTV.
"I'm not happy with the defending at the front. I think that's been one of our strengths this season but I thought that was non-existent in the second half.
"That needs sorting out because we don't want to be a team who is just defending in the box."
Solskjaer is optimistic of his side qualifying for the knockout stages of the competition.
"We're going to host them and go all out to get that win and the last two games we know we're through then," Solskjaer added.
"It's a great position to be in so far and we haven't conceded a goal so defensively we have done really well but we know we need to score more goals."
