The Owls’ Under-21s were beaten 2-1 at Barnsley on Monday afternoon.
A relatively even contest saw the home side emerge triumphant, with a late penalty proving the difference.
Earlier, Wednesday began well, with Keenan King and Ryan Meadows having half chances.
Jack Stobbs then went close with a free kick before the Reds took the lead against the run of play.
Barnsley were boosted by the breakthrough and bossed possession but the Owls then equalised out of the blue through Fraser Preston after the break.
But just as Wednesday pressed for a winner, they conceded a penalty that was duly converted, which was enough to seal victory for the Reds.
Wednesday: McDonagh, Booker, Beatson, Lachman, De Havilland, Anderson (Preston 58), Stobbs, Croasdale, King (Centeno 46), Marsh, Meadows