The 19-year-old defender was given oxygen as he was taken off the pitch, following a innocuous challenge from Seagulls player Enock Mwepu.
Hasenhuttl was not able to diagnose the injury following the game, but did say it looked “very serious”.
"“We are not sure yet, but it does not look good,” he said.“He’s very frustrated because he knows it could be a long break out. He will come back stronger.” (via BBC Sport)"
Livramento joined the south-coast club from Chelsea in the summer, and quickly broke into the first team, scoring his first goal against Burnley in October.
Since joining the club, the player has made 28 appearances, and made his U-21 debut for England.
It is not yet known how long the 19-year-old will be out for, but Southampton fans will be hoping to see the full-back, back on the pitch at Saint Mary’s by the start of next season.
In the meantime, the Saint’s don’t have too much to play for, but could still finish inside the top eight should they win their remaining games, three of which are against teams around them in the table.