Swansea boss Michael Laudrup rates defender Chico Flores as "very doubtful" for their trip to Saints, meaning Garry Monk is set to play against his former club on Saturday.
The Spaniard suffered a dead leg in the Capital One Cup win over Liverpool at Anfield and sat out last weekend's 1-1 draw with Chelsea at the Liberty Stadium.
And the 25-year-old looks set to miss the trip to St Mary's as he struggles to get over the knock.
Club captain Monk, who was at Saints from 1996 until 2004, has filled in during Flores' absence, impressing with his handling of Fernando Torres against the Blues.
Laudrup admits he has no concerns if Monk remains at the heart of his defence alongside Ashley Williams.
"Chico is very doubtful, he is still in lot of pain," said the Dane. "I knew when it happened against Liverpool it was very serious.
"Normally when you have a dead leg you get up and play on but then it is sore for three or four days.
"So when Chico had to come off I knew he was hurt, he wants to play every minute of every game. It was looking like eight or 10 days out so he is very doubtful for this weekend.
"There is no point risking him for one game if he is not right because we have lots of games coming up over the next few months.
"Garry came on and did very well. He did well against Liverpool and he did well against Fernando Torres together with Ashley."