Brighton boss Roberto de Zerbi admits Adam Lallana has suffered a heavy injury.
The veteran midfielder has suffered a leg injury in the past week.
"Adam Lallana has a bad injury and we have lost him for some time," said De Zerbi.
"Danny Welbeck is also unable to play. Levi Colwill may be back for the next game.
"Adam's injury is on the same part of the leg. I think we have lost him for several months."