Revealed: The lengths Jack O'Connell is going to to accelerate his Sheffield United recovery

O’Connell went under the knife to correct a problem that had been troubling him for some time last year, after playing just two games in the current campaign.

Without him, United have struggled badly and go into this weekend’s clash at Wolves on the brink of relegation to the Championship after falling 18 points behind fourth-bottom Newcastle United following Sunday’s 3-0 defeat at home to Arsenal.

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And United, who initially hoped to have O’Connell available to return this month, have refused to put a timescale on when he can pull on a shirt again after Paul Heckingbottom, their temporary manager, admitted that the next phase of the centre-half’s rehabilitation programme will depend on how he responds to the treatment over the coming weeks.

O’Connell has been undertaking pyramid HIIT (high intensity interval training) workouts in a specially-designed oxygen tent, with oxygen levels set at almost half of the normal atmosphere.

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A favoured training routine for high-endurance athletes, altitude training means that their muscles receive a natural boost when normal oxygen levels resume.

“Jack, at the moment, is still going through a process,” Heckingbottom said. “He’s doing that because there was a reaction, and everyone wants to make sure it’s right.

“He’s going through a step programme, and what happens depends on how those are completed. That is mapped out, but if it doesn’t work then he could be going down a different route.”

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