Match report: Coventry U18s 2-0 Villa U18s
Tony McAndrew insists the controversial sending off of winger Jack Grealish proved costly after his side produced their "best performance of the season" against Coventry.
With Villa well on top against the Barclays Premier Academy League Group B leaders, the talented 16-year-old was shown a second yellow card for simulation when he should have been awarded a penalty.
The hosts took advantage of the disparity in numbers as second-half goals from Courtney Richards and Will Roberts sealed a seventh straight win for the Sky Blues.
But the scoreline failed to tell the whole story of a game in which McAndrew's men created a host of chances.
Coventry had goalkeeper Lee Burge to thank for a clean sheet after he pulled off a succession of superb saves.
McAndrew said: "It was probably the best we have played all season.
"We didn't deserve to lose the game and we still can't believe we lost it.
"It was a really, really encouraging performance but certain factors and decisions changed the game.
"But the lads still stuck at it and we created the best chances with 10 men. I am proud of the lads' attitude and we played well."
The youth team coach described Grealish's sending off as "tough to take" as Villa had been well on top until that point.
He added: "The referee sent Jack off for a drive that was a stone wall penalty.
"We were in total charge of the game and we went from being in total charge to being 1-0 down with 10 men.
"It was a little bit hard to take when we were so far on top but that is life."
VILLA: Barrett, Bateman, Bryan, Donacien, Kinsella, Graham, Ward, Melvin, Grealish, Burke, Robinson. Subs: Darkin [for Robinson, 65], Barton [for Graham, 75], Eminoglu [for Ward, 85], Watkins, Nelson.