It did not look good for Newcastle boss Steve Bruce, screaming 'what the f*** is happening?' towards his backroom team as the left wing-back he had just brought on charged around the centre of midfield.

Eventually, after two minutes of confusion and much enthusiastic running from substitute Jetro Willems, a livid Bruce got his message onto the field.

Willems switched to his natural position and Matt Ritchie, a left-sided midfielder, came infield to fill the hole left by the injured Jonjo Shelvey.

Steve Bruce's first league game in charge of Newcastle ended in defeat against Arsenal

Just two minutes later and Willems, perhaps worn out from his midfield cameo, was caught on his heels and Ainsley Maitland-Niles stole the ball before breaking forward to set up Pierre-Emerick Aubameyang for the game's only goal.

'It was just a lack of communication with him,' said Bruce about the substitution. 'He only played there for two minutes really until we got the information down about where we wanted him to play.'

Bruce responded to Arsenal's goal by bringing on Allan Saint-Maximin, a winger, and withdrawing Sean Longstaff, another central midfielder, leaving only Isaac Hayden in the middle of the park.

Where was midfielder Ki, not named among the substitutes despite the presence of four defenders on the bench?

'Ki wasn't injured, he just wasn't part of the squad,' said Bruce. 'We had a knock to Paul Dummett and we had a worry over Jamaal Lascelles because he wasn't feeling too great. That's what we were guarding against.'

Arsenal edged to victory after Pierre-Emerick Aubameyang profited from Willems' mistake

The Gabonese striker pounced on a loose pass from Jamaal Lascelles to score the only goal

The final half hour, it has to be said, was shambolic from a Newcastle perspective. Saint-Maximin was supposed to be operating just off lone striker Joelinton but drifted to his preferred left-wing and was reminded by Bruce of the position he had asked him to play.

Miguel Almiron, who had been so lively in that role supporting Joelinton, was brought back into midfield and his impact soon waned. He gestured to the bench in search of answers as the team became ragged and gaping holes emerged.

At one point, Newcastle had no player on the right-hand side of the field as Ritchie, Maximin and Almiron - all left-footers - stood within yards of each other in their natural domain.

Bruce must take the blame for the clumsy introduction of Willems at St James' Park

The upshot was no concerted pressure, no late push for parity. It said much that, when four minutes of added time were announced, there was no rallying cry from the home support.

Still, this is one game. In isolation it was not good, but there were positives during a first half hour in which Bruce sent his team out on the front foot and they troubled the visitors.

And it was still going relatively well until the clumsy introduction of Willems seemed to affect Newcastle's rhythm. For that, the buck stops with Bruce.