Beaten by their neighbours, who went on to win the treble, it wasn&apost the dream ending the Reds had hoped for and you could be forgiven for thinking there was an element of exhaustion as well as disappointment on that May evening.
United had played a mammoth 62 games across four competitions, and it could have been higher had they reached the Europa League final instead of losing in the last eight. The Reds were not alone in their hectic workload with City playing one match more and West Ham also facing a heavy workload amid European successes.
The winter World Cup didn&apost help as the fixture list was condensed to fit the tournament in while the likes of United had plenty of representatives in Qatar. Thirteen Reds players started 27 games or more across last season and that tally would likely have been higher if Lisandro Martinez wasn&apost injured.
Ten Hag often selected his strongest side in cup competitions – a decision that paid off with extended runs in both and breaking the silverware duck by lifting the Carabao Cup. But the Dutchman can find a balance.
The second leg of the Carabao Cup semi-final, with United already 3-0 up, surely didn&apost require starts for Bruno Fernandes, Casemiro, Raphael Varane and Lisandro Martinez. There were other examples of where rotation could have been married with a result, the second leg against Real Betis for one.
If Ten Hag is to close the gap to City domestically and compete on the continent on United&aposs return to the Champions League, then he has to trust the squad he&aposs built. It&aposs not a perfect one by any means but allowing the likes of the aforementioned quartet and stalwarts such as Marcus Rashford a breather and handing more starts to players such as Facundo Pellistri and Sergio Reguillon along with promising youngsters Amad Diallo, Kobbie Mainoo, Dan Gore and Hannibal Merjbi can lighten the load on the senior stars.
Not only will it aid the development of others, it could help prevent injuries to those Ten Hag considers most important. It feels like United are playing with fire by pushing Bruno into action week-in, week-out and the intensity in which they want to bring under Ten Hag can lead to players breaking down. Some are just bad luck, Mainoo was caught in a challenge in pre-season, and the Reds have invested heavily in injury prevention techniques.
Sir Alex Ferguson was perhaps the master of rotation – keeping four strikers at the top of their game active during the 1999 campaign was a feat in itself. And while Ten Hag doesn&apost have the squad power United possessed then, there is a lesson to learn.
The Premier League is stronger now than it arguably ever has been and the Champions League brings an added layer of intensity and quality to United&aposs schedule. Ten Hag doesn&apost have the squad he desires, but he must ensure best use of what he does have at his disposal.
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The transfer window will soon close and although United got their hands on three players well in advance of the September 1 deadline, with Rasmus Hojlund joining Mason Mount and Andre Onana at Old Trafford, activity has stalled since Hojlund&aposs announcement.
A goalkeeper, a midfielder and a striker were Erik ten Hag&aposs priorities heading into the summer window, but injuries early on in the season mean United are in need of further reinforcements.
Our team of experts will be on top of all the goings-on at Old Trafford for the remainder of the window and beyond, and you can get the latest updates and inside information to your phone by joining our new free WhatsApp community below.