Southampton boss Ralph Hasenhuttl has admitted Stuart Armstrong is "50-50" to face Leeds United.
The Whites welcome the Saints to Elland Road on Tuesday night in a match that was originally due to be played in January.
Leeds will be hoping to return to winning ways after a 1-0 defeat to Wolves on Friday night, with Illan Meslier incredibly unfortunate to defect Adama Traore's shot into his own net after the ball had crashed against the crossbar.
The Saints, meanwhile, drew 1-1 with Chelsea, though Armstrong missed the match after missing training the week prior.
Hassenhutl said: "It is nothing serious. The only problem we have with him is his fitness. This is the biggest issue we have.
"We have to work on his physical fitness because two games in three days are a problem for him and when you want to be at the highest level you have to manage three or four games of this intensity.
"This is what he cannot do so far and he has to work on this because it is not perfect for a Premier League player."
When asked for an update on the midfielder's fitness, he said: "It's fifty-fifty. That is a lot for me, it doesn't sound a lot to you, but it's a lot!
"As far as I have seen we have no more injuries - but normally I get all good messages and then they come and tell me that we have a few issues.
"Hopefully, I don't see my doctor," he said with a laugh.
Theo Walcott, Ibrahima Diallo, Kyle Walker-Peters, Will Smallbone and Michael Obafemi will all miss the match too, with Hassenhutl confirming Walcott will not feature until next month.
When asked about the duo, Hasenhuttl said: "Diallo will be back a little bit earlier [than Walcott], I think. There is no tendon involvement.
"Theo will take a little bit longer," he said, on the player has confirmed earlier this month could remain out into March. Every player who comes back will help, definitely."
