Southampton midfielder Will Smallbone faces up to six months out with an anterior cruciate ligament injury, manager Ralph Hasenhuttl says.
"It's an ACL injury, so half a year out maybe," Hasenhuttl said. "It's horrible for the young lad and for us."
Danny Ings, Jannik Vestergaard, Oriol Romeu, Nathan Redmond, Moussa Djenepo and Mohammed Salisu are also sidelined.
"At the moment with these injuries, it is definitely not our best side to be honest," Hasenhuttl said.
"But there are maybe some circumstances at the moment in this strange season which lead to a lot of problems with injuries that we didn't have the whole of last season.