Stoke midfielder Delap and Sheffield Wednesday striker O'Grady have both signed on loan until the end of the season and could feature at Bloomfield Road.
However, John Stones will be unavailable after his deadline day move to Everton.
The Tykes extended their unbeaten run to five matches in midweek with a home win over Millwall and manager David Flitcroft has no new injury or suspension problems.
New signing Jason Scotland is pushing for his first start after stepping off the bench and scoring with his first touch on Tuesday night and midfielder Jacob Mellis is also hoping to play a bigger role.
Defender Bobby Hassell and Scott Wiseman will both return to contention after sustaining knocks in last weekend's FA Cup win at Hull and sitting among the substitutes against Millwall.
Midfielder Stephen Dawson (ankle) and defender Jim McNulty (hamstring) remain sidelined as the Tykes chase a third straight win.