Northern Ireland international Brunt was forced off in the second half of Wednesday's 1-0 victory over Coventry with an ankle injury and he has failed to shake it off in time for the trip to the Madejski Stadium.
Koren also sustained a calf problem against the Sky Blues and could join Brunt, Roman Bednar (thigh), Marek Cech (groin) and Gonzalo Jara (broken metatarsal) on the sidelines.
However, apart from Jara - who is likely to miss the rest of the season - Albion's treatment room is expected to empty out for the Easter period.
But there is good news for Roberto Di Matteo as defensive lynchpin Jonas Olsson has a chance of making a return against the Royals having missed the last two games due to a calf problem.
