Manager Jose Mourinho has claimed that he could feel the "little panic" when Arsenal entered Manchester United's defensive third at Old Trafford on Wednesday night.
United went into the game having failed to win in three Premier League outings, but Mourinho watched his side twice come from behind to earn a 2-2 draw against the Gunners.
Mourinho has praised his team's fighting spirit, but the Portuguese has hinted that he had been left concerned by the confidence of his backline.
The 55-year-old is quoted by BBC Sport as saying: "We scored four goals and drew 2-2. As always we made mistakes and we paid for the mistakes. Today was more the same, but with great spirit and people ready to have a go and fight hard, it was a credit to the team.
"They went to the limit and were really tired. Some of them had not played all season, Chris Smalling playing in very difficult condition, but Arsenal were only dangerous when we lost the ball in bad areas.
"This is a performance of big soul and heart, [Marcus] Rashford, just to give a name, gave everything for the shirt. But even from our bench you could feel the little panic when the ball comes to our defensive third."
United remain in eighth position in the standings.