Smith Rowe was shown a red card for a challenge on Newcastle’s Sean Longstaff, but after the pitchside monitor was used it was downgraded to a yellow and the youngster made the most of his reprieve to help the Gunners through to the fourth round.

Only nine of the 32 ties across this weekend will have VAR – those played at Premier League grounds.

And Arteta said: “I was going mad because when I saw the action on TV, I didn’t think that he could get sent off but thank God the regulators decided to have VAR and today it worked the way it should work, so I am so happy to have that.

“We believe in Emile, he is doing really well. He is growing and becoming more and more important in the team.

“Today he showed that again the way he came on, the personality that he played with and we asked him to be more in the box, more of a threat in front of goal and he scored a really important goal for us.”

Smith Rowe was the first person Arteta turned to on the bench following a drab hour of play at the Emirates Stadium, where chances were at a premium.

His introduction, coupled with Bukayo Saka and Granit Xhaka coming on later in the half, helped Arsenal start the defence of their title with a 2-0 win.

Captain Pierre-Emerick Aubameyang had been a peripheral figure before Arteta called for the cavalry but grabbed his sixth goal of the season with a 117th-minute tap-in from Kieran Tierney’s centre.

It was another positive for the holders, but they were dealt a blow before kick-off when Gabriel Martinelli, who only recently returned from a serious knee injury, suffered an ankle issue in the warm up and was forced to miss out after being named in the starting XI.

Arteta admitted: “I am gutted. I was in my office before the game and one of the coaches came in and said Gabi hurt himself and twisted his ankle.

“I went to the medical room and he was in tears and in a lot of pain. We are going to have to see how he is. It didn’t look good, he was in pain so I imagine we are not going to get good news with him.”

Martinelli will go for a scan but is expected to miss Thursday’s home fixture with Crystal Palace in the Premier League.

“It is his character that he wants to play the next game, that he doesn’t care and can handle pain,” Arteta said.

“Hopefully there is nothing too serious, but to start with it didn’t look good.”

Steve Bruce could not hide his disappointment at a missed opportunity for Newcastle, with Andy Carroll guilty of squandering two excellent chances.

The Geordie scored his first goal for the club in 10 years during last weekend’s home defeat to Leicester and could have added to his tally first in the 56th minute, when he side-footed a Jeff Hendrick cross wide, and let an even better chance slip in stoppage time when he failed to beat Bernd Leno from close range.

Bruce said: “When you come here, especially for a cup tie, and when you are presented with the opportunities we had, you hope you can take them.

“I couldn’t be more pleased with how they went about their work but we just needed to take the big opportunity when it came along.

“Nobody is more disappointed than Andy that he didn’t take one, but his overall play and the way he led the line was terrific. It would have capped a great week for him.”