Andrea Orlandi has been ruled out of Albion's key home game against Reading tomorrow.
Fellow central midfielder Dale Stephens is also expected to miss the match.
Orlandi has not recovered from a thigh injury.
The gifted Spaniard has been used recently by head coach Oscar Garcia in the central midfield role he prefers.
Stephens, signed from Charlton in January, has a foot bone injury.
He could be fit for Tuesday's clash against QPR at the Amex.
Oscar is also cautious about Rohan Ince returning, even though he is back in training after an ankle problem.
Oscar said this morning: "He is 50-50. Him and Dale are doubtful. Andrea Orlandi will not be available for selection."