The Portuguese international suffered a hamstring injury in the Saints' last Premier League game against Chelsea. Soares took to Twitter to explain his situation and thanked the fans for their support through the tough time.
The ex-Sporting Lisbon man has already faced time out this season with injury, and this current blow could not have come at a worse time for his team.
Soares will be sorely missed by his teammates. The right-back has been on top form in recent weeks, and was rewarded for his efforts recently by being named Southampton's player of the month for November.
The Saints currently sit 12th in the league, with only three points between themselves and 18th placed Newcastle United. Up next is Huddersfield Town at home, and manager Mauricio Pellegrino will undoubtedly be looking for a response from his team following a poor run of form, which has seen them go five games without a win.