The Reds could not secure promotion via the playoffs and remain in League One, while their opponents' second-place finish means they will compete in the Championship in the 2024-25 campaign.
Match preview
After only taking charge of the Tykes at the backend of last season, Darrell Clarke is still in his honeymoon period as Barnsley head coach.
The Reds were stopped by Bolton in the semi-finals of the playoffs, and they had to stew over that disappointment all summer.
The Colliers returned to pre-season keen to get off to a strong start, underscored by commendable wins over Alfreton (3-1) and Accrington Stanley (3-0), only for draws against Gainsborough (3-3) and a loss to Mallorca (1-0) to dampen some of the rising optimism.
While they still netted three times in the draw, Barnsley firing blanks against their Spanish opponents last time out may have raised eyebrows in some quarters.
Clarke hopes his players show that the reverse against Mallorca was nothing but a one-off result.
The opposition heading into Wednesday are Paul Warne's Derby, who secured a return to the Championship after ending last season as runners-up in the Championship.
Last season's meetings were split, with the Rams beating Barnsley 3-0 at Pride Park but losing the game at Oakwell 2-1.
However, the February loss to the Reds did not derail their promotion ambition, as Warne guided the club to their highest-ever points return in the club's history.
Derby began pre-season with wins over Matlock (3-0) and Stockport (1-0) sandwiching the the 3-1 loss to Academico Viseu but they hope to return to winning ways after the recent losses.
Having kept two clean sheets before the defeats to Chesterfield (4-0) and Shrewsbury Town (2-1), Warne hopes his side return to that level of performance as they play for the sixth time in the off-season.
Barnsley friendly form:
Derby County friendly form:
Team News
Josh Earl netted just twice throughout last season, but the defender netting in preseason wins over Alfreton and Accrington points to an improvement in that regard in the forthcoming season.
However, the defender's remit — along with other players in the backline — is to keep goals out, and that is the home side's aim after letting in four in the last two matches.
Warne's men have spread the goals around in pre-season and that stands the Rams in good stead for the forthcoming campaign, with Sonny Bradley, Jerry Yates, Liam Thompson, Kayden Jackson and James Collins finding the net in the team's four games.
The Rams are expected to line up in a 3-4-1-2 in Wednesday's friendly match, effectively matching their hosts.
Barnsley possible starting lineup:
Smith; Shepherd, Lopata, Earl; Lofthouse, Connell, Russell, Cotter; Craig, Jalo; Watters
Derby County possible starting lineup:
Vickers; Nelson, Cashin, Forsyth; Ward, Osborn, Ozoh, Barkhuizen; Blackett-Taylor; Yates, Collins