The Reds fell to a narrow 1-0 defeat at Hull City in a pre-season friendly on Tuesday evening.
A goal just after the half-hour mark by Will Jarvis was enough to see the Tigers emerge as winners.
The majority of the play in the opening exchanges was in the hosts' half, and the Reds pressure almost culminated in an early opener for Oli Shaw.
Liam Kitching recycled the ball well to Nicky Cadden on the left who demonstrated clever skill to beat Lewie Coyle and delivered a sharp, low cross across the face of goal which found the Scottish striker inside the six-yard box, but he blazed his effort over the bar.
Midway through the first half it was the Reds who came closest again, James Norwood letting fly from 25 yards and forcing Matt Ingram into an acrobatic save with the attempt looking destined for the top corner.
However, it was Hull who broke the deadlock in the 31st minute. Coyle delivered a ball from the right which found Jarvis at the back stick and he made no mistake from close range.
Jarvis nearly doubled his tally for the evening in a similar fashion, but Ben Kilip produced a wonderful fingertip save to prevent the lead from extending before the break.
HALF-TIME: Hull City 1-0 Barnsley
A number of changes out on the pitch for the Reds in the second period disrupted the rhythm of the game established during the first 45, with neither side threatening the goal.
Fabio Jalo was the next to spring a 'keeper into action, forcing substitute Thimothée Lo-Tutala into a smart stop down to his right from a long range free-kick.
Hull almost doubled their lead late on via Liam Delap but for a heroic block from Jack Shepherd inside the six-yard-box in the centre-half's first showing for the Reds.
Despite an encouraging and spirited performance from the young Reds, City kept their advantage before the referee blew his whistle promptly as the clock ticked to the 90 minute mark.
FULL-TIME: Hull City 1-0 Barnsley
REDS XI (First Half): Killip (GK), Cotter, James, Lopata, Kitching (C), Cadden, Phillips, Connell, Kane, Norwood, Shaw.
Subs: Hayton (GK), Pickard, Leya Iseka.
REDS XI (Second Half): Killip (GK), Trialist, Joof, James (Pickard, 83), Shepherd, Winfield, Makiessi, Chapman, Trialist, Marsh, Jalo.
Subs: Hayton (GK), Doyle, Leya Iseka.
