Foster missed the 2-2 home draw with Newcastle last week due to a cut eye that required six stitches but the defender is back in contention for Selhurst Park.
Bobby Hassell, back to full fitness himself following an Achilles problem, returned to the starting line-up against Newcastle and capped an impressive display with an 87th-minute equaliser, so he will be hoping to retain his place.
Robins, who has no other new injury or suspension problems, will be loathe to make too many, if any, changes to his side.
Barnsley turned in one of their best displays under Robins in the second half against Newcastle and are aiming to extend their unbeaten league run to seven matches.
