Albion will be without Greg Halford as well as Solly March for Birmingham's visit on Saturday.
Utility player Halford has not recovered from a knee injury sustained on his comeback from a calf problem as a substitute in the closing stages of last Saturday's 0-0 draw at Sheffield Wednesday.
Manager Chris Hughton said: "Greg will unfortunately miss the game. He took a knock to his knee but it is only a knock.
"We don't expect it too be long. He'll miss Saturday but hopefully be back on Tuesday (home to Leeds)."
Hughton has confirmed the lengthy absence of March, reported earlier on The Argus website, with an injury related to the calf damage he suffered early on in the last home game against Nottingham Forest.
Hughton said: "We're just waiting on final scans but he'll certainly be out for a period of weeks.
"He was fairly sore. We were hoping it was going to settle down but it's ended up being more sore than we thought and taken a lot longer than we thought."
Kemy Agustien remains a long-term absentee with a recurring thigh problem.
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