After taking charge of Newcastle United for the first time in a competitive game, Steve Bruce was disappointed with the mistake that cost them the game against Arsenal.
Newcastle had a bright first half, creating a couple of chances, although they struggled in an attacking sense in the second period.
But, Unai Emery's side were far from their best and it was a mistake from debutant Jetro Willems that allowed Pierre-Emerick Aubameyang to win the game for the Gunners.
Bruce explains the Willems confusion
It was perhaps surprising when the Magpies boss took of Jonjo Shelvey, who had come so close to scoring in the first half after hitting the post.
Not only that, but it was Willems who replaced him to make his debut, whilst the left-back played in Shelvey's position as part of the midfield three for a few minutes.
Bruce has admitted that it "was just a lack of communication with him.
"I wanted to put Matt Ritchie inside and play him [Willems] in his position.
"He only played there for two minutes really until we got the information down about where we wanted him to play.
"That was quickly sorted out, not a problem."
Debutant involved in the 'mistake'
Willems signed for Newcastle in the summer window from Eintracht Frankfurt on a season-long loan with an option to buy.
Although, he was involved in the mistake that leads to Ainsley Maitland-Niles collecting the ball for the away side before picking out Aubameyang.
Bruce admitted to the error and the frustration that it caused due to it losing his side the match.
"We’ve made a genuine mistake," he said.
"Whether the pass was too short or whether he hasn’t reacted quick enough, at the end of the day I can’t criticise anybody for making a mistake.
"I thought his position to start with was too high, and made the ball longer than what it should have been.
"It’s something we can work on."
The former AFC Sunderland manager also went on to explain why three of his summer signings were left on the bench for the season opener.
"The reason why most of them weren’t playing today is that they’ve only been here four or five days.
The longer we get, the longer we can work together, we can iron out those things that need to improve," he added.
Ultimately, the manager felt that his side did not deserve to lose the game.
"The big disappointment for us all is to lose it in the way we did.
"It was a mistake. We’ve defended fantastically well throughout the game, I can’t really remember my goalkeeper making a save, and that against Arsenal is a big, big positive."
Newcastle will face Norwich City on Saturday for their second game of the 2019/20 Premier League season.