"It was an absolutely shocking, woeful display. Maybe some of the boys were thinking about their holidays already," McLeish told BBC Sport.
"That team needs a change and there will be change. That wasn't an Alex McLeish team today. We need to bring more quality into the squad.
"We've got through a really tough season. I've won lots of trophies as a player and manager and I haven't turned into a bad manager overnight."
McLeish joined Villa at the start of the season from local rivals Birmingham City.