The 21-year-old has scored two goals in 13 appearances for Steve Tilson's side since joining the Shrimpers at the beginning of September.
He will now remain at Roots Hall until December 8 but Tilson has hinted in the past that he may look to make the switch permanent in the January transfer window.
Hal Robson-Kanu and Lee Sawyer will return to their parent clubs after Saturday's match against Tranmere Rovers when their three-month loan agreements come to an end.