Villa managed to claim victory through a single first half goal that came from a corner, while working hard out of possession to continually frustrate a United side that had been unbeaten through seven domestic games so far in 2025/26.
Skinner suggested that the standard of performance fell just below what United fans have been used to seeing over the past few months.
"It's something we'll look at," he said.
"What I think about this team is they're honest [with themselves]. They'll work, and we'll work to fix things we didn't do so well today.
"Little things, like Villa played direct over our press, we weren't aggressive enough in the duels, which allowed them to get territory.