Alan Biggs: England squad has a Jack O’Connell-shaped hole

Jack O’Connell’s continuing absence is a symbol not only of what United have missed but potentially his country as well, despite their Euros surge.

And as the Blades go, very much the biggest miss and the biggest hole to fill for new boss Slavisa Jokanovic.

At the heart of the issue is a continuation or not with 3-5-2 because O’Connell, as his absence last season proved, was absolutely pivotal to that system.

But, of course, more important still is the hope for his eventual recovery from an extremely serious knee injury.

Before the 27-year-old was sidelined and underwent surgery just two games into last season, the former England Under 19 international looked nailed on for a call up to Southgate’s senior squad.

As Chris Holt recently argued in the Sheffield Star, I’d also have picked him without hesitation. Not sure I’ve ever seen a player quite like him actually.

Built like a locomotive, with the speed of an express train, Jack’s been a thundering presence the whole length of a football field. No little skill and control either, with a wonderful ability to cross a ball, and an indomitable spirit.

For me, this one player more than any other defined United’s rampaging success under Chris Wilder and also their collapse to relegation.

The one unavoidable weakness of the revolutionary overlapping centre back system devised by Wilder and Alan Knill is that it demanded enduring fitness from the key components within it.

O’Connell proved absolutely irreplaceable. Same with the equally outstanding Chris Basham on the other side of John Egan.

Without either of them, United just became an ordinary football team and, in Premier League terms, a very ordinary one at that.

And where do you go to replace an overlapping centre-back? They’re not in the agent’s catalogue, as far as I can see.

Jokanovic still has Basham, but can the system be played in mono rather than full-blast stereo?

It’s looking like we might see something more conventional in future, whatever formation Jokanovic decides to operate.

And, of course, it is possible to prosper with three centre backs in a more orthodox pattern.

Indeed, the greatest quality Southgate’s England have shown, besides having top class individuals and a wonderful group ethic, is adaptability.

The system is interchangeable, showing it’s players rather than formations that win football matches - and that has to be a pointer to the way ahead at Bramall Lane as well.

But main thoughts here with O’Connell in the hope that somehow he can piece back together a brilliant career.