Mourinho dropped high-profile duo Paul Pogba and Romelu Lukaku after recent disappointing performances which have brought only three points from the past 12 available – and, while quality was lacking, no-one could doubt his side’s endeavour and character.
Goalkeeper David de Gea made an uncharacteristic error as he failed to deal with Shkodran Mustafi’s tame 26th-minute header, which Ander Herrera could not clear before it crossed the line.
United were swiftly level through Anthony Martial after Arsenal keeper Bernd Leno could only half-clear a free-kick to set up an exciting second half.
Substitute Alexandre Lacazette scrambled Arsenal back in front after 68 minutes but United were on terms once more within seconds as Jesse Lingard pounced on Sead Kolasinac’s attempted backpass.
De Gea redeemed himself with a succession of fine saves as both sides had to content themselves with a point, with United now eighth in the Premier League and Arsenal, who extended their unbeaten run this season to 20 games, dropping to fifth.
“As always we made mistakes and we paid for the mistakes,” said Mourinho.
“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.”
Mourinho demonstrated he would not shy away from taking the big decisions as Pogba and Lukaku were consigned to the bench – he will have known the spotlight would have shone on him in unforgiving fashion had United lost.
In the end, it was a performance that was satisfying in parts but merely emphasised just how far United are behind the pacesetters.
United may not, as Mourinho complained, have any “mad dogs” in their side, but there was at least some bite about this display after recent tame efforts against Crystal Palace here, and at Southampton.
That was appreciated by United’s fans as a starting base, but there was little to suggest this was a team whose season was about to burst belatedly into life.
United’s attack was more fluid and mobile with Martial and Marcus Rashford selected ahead of Lukaku but there was still a lack of creativity, and while the effort was there, the real spark was missing.
Mourinho will be pleased at the manner in which United responded to Arsenal’s goals, helped by the Gunners’ sloppiness, and these were players who were undoubtedly putting in the work for their manager.
This is, however, a pale shadow of a side that will chase the big prizes.
Arsenal will, ultimately, probably be happy with a point at a ground where their recent record is miserable, and against opponents who were attempting to put down a marker after recent criticism.
Gunners boss Unai Emery, however, will feel disappointment that they did not leave with all three points after twice holding the advantage only to concede it quickly.
Emery’s frustration was obvious when Lingard scored United’s second equaliser moments after Lacazette had restored their lead, as he knew had they held their advantage a little longer there is every chance United could have become frustrated.
The manner in which it was conceded will have also infuriated the animated Emery, United striking back right from the kick-off with the aid of Kolasinac’s error.
On the plus side, Arsenal coped well with United’s predictable late aerial siege and this is a point that consolidated their good start to the season and extends that fine unbeaten sequence.
Emery may have wanted the win as Arsenal failed to reproduce the electrifying form that beat Spurs in the north London derby but there was still plenty to satisfy him.