Mikel Arteta shows Liam Rosenior the size of the task at hand at Stamford Bridge

In the build-up, everything went beautifully. Liam Rosenior, Chelsea’s new coach, stared out from the front cover of the programme for this Carabao Cup semi-final first leg against Arsenal, looking thoughtful and studious and confident in a smart jacket and a casual shirt on the occasion of his first match in charge at Stamford Bridge.

If body language is important, then Rosenior struck all the right notes. As his players walked back to the tunnel after their pre-match warm-up, Rosenior was waiting for them on the touchline, shaking hands with every one of the squad as they passed him, and his backroom staff, too.

Then, when the stadium joined in a minute’s applause for former Chelsea winger Eddie McCreadie, who died this week, Rosenior beckoned all the substitutes to join him and his staff on the touchline to pay tribute to a legend of the club.

His arrival has brought at least hints of optimism amid the misgivings about the ownership. The announcers did their bit to try to help with identity, playing Our House by Madness and, as always, London Calling, by The Clash. Some sang along as they watched flames shooting up from the side of the pitch.

Things went downhill from there for Rosenior.

All the feelgood stuff, all the benefits of emotional intelligence, disappeared into the cold night air inside seven minutes. Declan Rice swung over a corner with pace and precision into the six-yard box. Robert Sanchez flapped at it. Ben White leapt for it. Joao Pedro did not. And White headed it down, like you see in a text-book, and over the line.

The goal prompted a rash of comments about Set-Piece FC – it was their 24th goal from a set-piece this season and their 18th from a corner - but it is hardly Arsenal’s fault if opposition teams cannot cope with their corners and free-kicks. That was only half Chelsea’s problem anyway.

Every time the home team tried to play the ball out from the back in the way that Rosenior favours – and Maresca favoured before him - they courted danger. Arsenal rushed them and harried them and forced them into mistakes and spread anxiety in the crowd.

This was always going to be a tougher baptism for Rosenior than Saturday night’s 5-1 stroll at The Valley against Charlton Athletic in the FA Cup third round. Arsenal are the best team in the country. They are 18 points clear of Chelsea in the Premier League. This was always going to be tough for Rosenior. And that is how it proved.

After conceding the opener, slowly Chelsea gained a foothold in the game. Joao Pedro latched on to a through ball in the Arsenal area, spun neatly and hit a shot across goal that was begging for a final touch which did not materialise. A few minutes later, Estevao Willian lashed a piledriver at goal which Kepa Arrizabalaga did well to beat away even if it was straight at him.

The fans’ impatience with the attempts to play out from the back grew with every time Chelsea appeared to flirt with disaster in the face of Arsenal’s relentlessly honed press but four minutes after the interval, Arsenal doubled their lead with a move that started with a throw-in.

Bukayo Saka ran on to it and turned Marc Cucurella, who had been booked for fouling him late in the first half, inside out. Saka paused, waiting for the overlapping run of Ben White, and timed his pass perfectly.

White slid the ball across goal and Robert Sanchez spilled it when he should have claimed it. The ball squirmed out of his grasp and into the path of Gyokeres, who could not miss. He hammered it over the line from two yards out.

Rosenior stood on the touchline, hands thrust deep in his pockets. The Arsenal fans massed in the Shed End enjoyed his disappointment. ‘You’re getting sacked in the morning,’ they sang at Rosenior.

But Arsenal could only preserve their two-goal cushion for eight minutes. Pedro Neto broke down the right and his floated cross into the box caused havoc. The ball fell to substitute Alejandro Garnacho at the back post and he rifled his shot low past Arrizabalaga.

That gave Chelsea hope but they could not cling on to it. Twenty minutes from time, Gyokeres laid the ball off to Martin Zubimendi in the Chelsea box and Zubimendi drifted to his left before hitting an unstoppable shot past Sanchez to put the visitors 3-1 up.

They nearly made it four when Mikel Merino ran on to a lofted pass and caught the ball sweetly on the volley. It looked like a certain goal when it left his boot but Sanchez redeemed himself a little for his earlier mistake by diverting the shot past the post with his legs.

Arsenal soon had reason to curse their profligacy. Eight minutes from time, it was their turn to fail to defend a corner and when the ball fell to Garnacho he drilled the ball past Arrizabalaga for his second of the evening to bring the deficit back to 3-2.

Try as they might, Chelsea could not force an equaliser. It was a tough night for Rosenior. Arsenal showed him the standard he knows his team must reach but he will have been encouraged by their refusal to wilt.

He and his Chelsea team will need all that determination and resilience if they are to have any chance of overturning Arsenal’s advantage at The Emirates on February 3 and making it to Wembley.