Saphir Taider's loan deal at Saints has been terminated after less than a month, the club has confirmed.
The 22-year-old moved to St Mary's from Inter Milan in early August, but is now returning to Italy after the club agreed to end his spell with them.
The Algerian international's arrival had coincided with Dani Osvaldo going in the opposite direction, with the latter deal remaining unaffected.
A statement from the club said: "Southampton Football Club can confirm that it has agreed to terminate midfielder Saphir Taider’s loan spell.
"The midfielder joined Saints for the 2014/15 campaign but, having failed to live up to the high levels of commitment expected of Southampton players, that arrangement has been cut short by the club.
"Taider, whose only first-team appearance came in the friendly against Bayer 04 Leverkusen earlier this month, now returns to parent club Inter Milan. Dani Osvaldo’s loan arrangement with the Italian side is unaffected."
Saints boss Ronald Koeman said at the weekend: “It was a difficult situation for him.
“I can’t guarantee players to play. We have competition and a lot of good players and you have to show you have to play.
“I always have in mind to put out the best starting line-up and it’s a competition and we need everybody.
“If you show that then it’s no problem but if you can’t accept that then that’s difficult.”