Arsenal lost to Manchester United at Old Trafford on Sunday afternoon after a last-gasp header from Marouane Fellaini sealed the three points for the hosts.

Jose Mourinho’a side consolidated second place moving to 77 points as the Gunners remained sixth, remaining on course for their lowest points total for more than a decade as they lost their sixth consecutive away league game.

The winner came after a second-half strike by Henrikh Mkhitaryan had cancelled out a Paul Pogba header from the opening 45 minutes.

It was understandable that Arsene Wenger fielded a weakened Arsenal side against The Red Devils with the huge Europa League semi-final clash against Atletico Madrid on Thursday.

After all, long gone are the days when the whole world stopped to watch the matches between these two giants, who are rivals only in name these days.

Their often vicious, but always compelling, clashes for the title made compulsive viewing with no quarter given nor asked.

The recent Fergie v Wenger programme on Channel 5 also made for gripping television. What was instructive was the absolute bitterness Paul Scholes still harboured against the Arsenal, such was the intense completion the two teams showed.

However, time moves on and mellows the hardest of hearts, for even that old firebrand Roy Keane spoke of the respect between the two sides here.

There was also the heart-warming sight of Sir Alex Ferguson greeting his old rival Wenger on the pitch before the match.

The respect and camaraderie shown between the two was admirable as it was heartening. Certainly for those of a certain vintage who can still recall the utter hatred both giants of the game showed towards each other in their heyday.

And now all that is left is the war stories of two veterans who ruled English football for decades.

What was also noticeable in their pre-match meeting was the fact Jose Mourinho was absent.

Yes Mourinho slapped Wenger on the back in a faux show of bonhomie, but his constant belittling of the Frenchman in the early years of their rivalry after the Portuguese boss started to make his mark in English football in the wake of the Invincibles hurt Wenger for the deeply personal nature of the animosity.

It is something he has yet to forgive Mourinho for completely, given by the elongated pause Wenger involuntarily issued when asked his views on the United bosses’ testimonial after the Atletico home match.

However, there was also another reason why Wenger gave his £2million January signing Tino Mavropanos his debut and rested Mesut Ozil, Aaron Ramsey, Jack Wilshere and Alexandre Lacazette from their sterling – if not decisive – efforts at a raucous Emirates 72 hours previously.

The Premier League match against United simply didn’t matter in the scheme of things.

The focus is all this coming Thursday night against Atleti in the crucial second leg of the Europa League semi-final where Arsenal need to show courage against Diego Simeone’s excellent La Liga side.

It didn’t mean a thing if Arsenal lost 2-1, 8-2 – or any other score for that matter.

Which was just as well after the Red Devils went ahead through Pogba’s header on 15 minutes.

While the goal reflected United’s dominance the goal itself was slightly fortuitous as Hector Bellerin’s block from Alexis Sanchez’s header diverted the ball onto David Ospina’s right hand post.

Personnel from the visitors defence was markedly absent when the ball rebounded back off the woodwork to allow Pogba – a former United academy player who was bought back from Juventus for £80m – to head home and break the deadlock.

United threatened throughout the remainder of the half without adding to their total, while Arsenal posed questions if not problems down the left through the former Red Devil Mkhitaryan.

The warning was not heeded early in the second half when the fit again Armenian fired across David De Gea, wrong-footing their acclaimed goalkeeper to equalise.

Thereafter the match was a strange assortment of scrappy play punctuated by flashes of excitement as the teams subsided to a draw being the height of their ambition – and nearly achieving it with plenty to spare in front of 75,035 fans.

However substitute Fellaini had other ideas and headed home with moments remaining after climbing higher than the Arsenal backline in a crowded box.

There was an element of fortune about the winner as the big midfielder was facing away from goal. But no-one assembled among the home support cared a jot about that as they clinched victory.

Both Mourinho and Wenger have different – not bigger – fish to fry in the merry month of May.

Which is a sad indictment on the standing of these two clubs, even if the Europa League and the FA Cup are still on the agenda.

Arsenal: Ospina, Bellerin, Mavropanos, Chambers, Kolasinac (Monreal 63), Maitland-Niles, Xhaka, Mkhitaryan (Willock 76), Nelson (Welbeck 63), Iwobi, Aubameyang. Unused subs: Holding, Cech, Nketiah, Osei-Tutu.

Attendance: 75,035.