The 24-year-old joined the North London side from United for £16m last summer and has been in superb form this season, having been deemed surplus to requirements by Louis van Gaal at Old Trafford.
Having scored in midweek for England, Welbeck has now credited his scoring form to the regular football he receives at the Emirates stadium.
“When you are playing regularly, you feel a lot sharper on the pitch”, he said.
“Once you play regularly, it just becomes second nature to do things on the pitch. I feel match-sharp and that is important.”
Welbeck then went on to praise Tottenham Hotspur striker Harry Kane, who scored on his England debut against Lithuania on Friday evening.
“We’ve got great options,“ said Welbeck. “And it is not just the attacking players, but it is all over the pitch. With the way we are playing at the moment, if you get a chance you want to take it.
“Harry? He got a great reception when he came on. He scored and everyone is delighted with him.”