The 31-year-old Brazil-born forward has struggled for first-team action under Saints boss Mauricio Pochettino and his chances of forcing his way into the Argentinian's plans have now been hindered by this injury.
Do Prado has not featured for the Saints since making a 78th minute substitute appearance in the 2-0 win over Fulham on October 26 and he will now be sidelined until the New Year.
The player, who joined the Saints from Cesena on an initial loan deal in August 2010, will hope to steer clear of any more injuries on his return to action as he will be out of contract next summer.
Therefore he will hope to get some games under his belt to try and earn an extension at St Mary's or attract interest from other clubs.
Southampton last week