Ole Gunnar Solskjaer is quickly discovering there will be no quick-fix long-term solutions after taking over from Jose Mourinho.
But one thing Solskjaer has championed is the return of sports science, something Mourinho always resisted during his time at Old Trafford.
Solskjaer has brought back equipment made by Irish company STATSports and the results and improvement of player performance during games are startling.
Under Mourinho in the Premier League this season, United averaged 99 sprints per game.
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But now Solskjaer is in charge, they have averaged 110 sprints per game. That is more than a 10 per cent improvement which industry experts insist is hugely significant.
Manchester United manager Solskjaer, meanwhile, is dreaming of another memorable comeback in the Champions League but has admitted his side cannot afford to squander opportunities.
Barcelona did not deliver a vintage performance that has been their hallmark for over a decade but came away from Old Trafford with a 1-0 win after the first leg of their quarter-final following Luke Shaw's 12th-minute own goal.
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United showed plenty of endeavour in attempting to equalise but failed to hit the target, with Diogo Dalot and Marcus Rashford both guilty of spurning decent opportunities when well placed.
Solskjaer knows opportunities will be at a premium when the teams meet again at the Nou Camp next Tuesday but is optimistic they can upset the odds - as they did last time out when overturning a two-goal deficit against Paris St Germain.
Barcelona's ground holds a special place in Solskjaer's heart after his last-gasp goal there sealed United's famous Treble almost 20 years ago, leading the Norwegian to say: "We've scored goals at the Nou Camp before from corners and crosses.
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"Of course the PSG performance away gives us hope and belief that we can do it. But we know that we are playing against the favourites in the tournament.
"Going to the Nou Camp is going to be a challenge and it will be a greater achievement winning that one because with the history of Barcelona as well, they're not used to losing at home.
"But we can do it, no doubt about it, we know we can carry a goal threat."
