Albion midfielder Katie Robinson will miss the rest of the season after suffering an ACL injury in training.
The 18-year-old, who joined the Seagulls from Bristol City in the summer, made her WSL debut in the 2-0 win over Birmingham City earlier this month.
The England youth international will undergo an operation in the next few days.
Head coach Hope Powell said, "It's very disappointing for Katie, who had come to the club in pre-season and settled in really well.
"We wish her all the best for the surgery and her rehabilitation and we will support her every step of the way in her recovery."
Robinson made her England under-17 debut in 2018 and scored England's third goal in a 6–0 win against Moldova. She has made 11 appearances for the under-17s and scored eight times.
Robinson previously made 17 Women's Super League appearances for Bristol City after coming through their academy.