The 33-year-old limped out of Tuesday night's 2-1 defeat to Brighton with a groin injury and is a doubt to face the Shrimpers.
Akpo Sodje replaced Burton and could keep his place in the side, while Leon McKenzie is also pushing for a start.
Defender Frazer Richardson was suffering with a tight groin before the Brighton clash, and despite playing 70 minutes, will be closely monitored before the trip to Essex.
If Richardson is not fit then Jose Semedo and Chris Solly are waiting in the wings after being on the bench in midweek.
Fellow defender Grant Basey remains on the sidelines with ruptured ankle ligaments.