Austria Under-21 international Weimann curled a 20-yard shot past Stoke keeper Asmir Begovic to give Villa a first-half lead in only his second senior start.
McLeish said: "Goals talk and it will be hard for me to leave Weimann out.
"It was a fantastic strike. We needed a bit of inspiration at that time and it was inspirational.
"It came out of nothing and was a wonderful goal from a great young prospect. He is a good finisher and we've seen it again with that goal."