The forward had failed to score a Premier League goal in 2018 but struck twice in his side's 3-2 triumph at the Emirates Stadium, including heading in the winner in the 81st minute.
He has been beset by injury problems in the past two seasons and he has rarely figured for England since playing a leading role in the qualifying campaign for Euro 2016.
"The World Cup will take care of itself - I don’t pick the team," he told Arsenal's official website.
"My mind is set on the next game, doing well in those games.
"Going into the Europa League on Thursday, it’s going to be a difficult tie even though we won the home game [4-1]. It’s going to be a difficult game so our minds are set on that."
Welbeck failed to take a glorious chance to score when the game was locked at 2-2, diverting Jack Wilshere's volleyed cross wide of the target from inside the six-yard box.
Yet he made amends for the miss soon after, nodding in Alex Iwobi's deep cross to the back post.
"I thought there’d be another opportunity to get a goal and get the winner. I kept my mind focused on that," he said.
"Obviously you’re disappointed, but then it’s gone and you can’t do anything about that. You have to move onto the next one."