Jack O’Connell can be found on his days off hitting the pads in an old-school boxing gym in north Liverpool which, on Thursday morning, is home to aspiring fighters, one mixed martial arts world champion and a footballer who will be facing Manchester United on Sunday.

O’Connell is the Premier League success story you may not have heard of, unless you happen to be a Sheffield United fan. A left-footed centre-back, he has played every minute of all 12 games in his first top-flight season, and he is ominpresent in Opta’s rankings for defenders. His touchmap on any given game is a thing of wonder for a centre-half – speckled heavily down the left wing. He does all the conventional defending as well as being one of Chris Wilder’s famous overlapping centre-backs.

He pauses for a breather and leans on the ropes. Come the next day he will be preparing to face Marcus Rashford, Antony Martial and the rest, but this is how he loves to keep sharp for Sheffield United, currently in fifth place and something of a revelation. No newly-promoted team have conceded fewer goals after 12 games – nine – and that only tells part of the story.