Southampton midfielder Romeo Lavia is set to be out for at least six weeks with the hamstring injury he suffered in Tuesday's 2-1 win over Chelsea.
Lavia has started all five Premier League games for Saints since joining from Manchester City this summer.
"Romeo is injured now, but has shown he can be a massive part of our game," said manager Ralph Hasenhuttl.
"He will be out for longer - how long we will see, but I expect minimum six weeks."
Lavia was one of 10 summer signings for Saints, with four deals completed on deadline day on Thursday.