With skipper Doug Loft suspended, manager Micky Adams could be forced to make three changes from the team held to a goalless home draw by Bradford on Tuesday night.
Full-backs Richard Duffy and Dan Jones are both doubts ahead of the weekend visit of the Shrimpers having missed training on Thursday.
"We'll give them as long as we possibly can, but both must be doubtful," said Adams.
"Dan looks as though he's tweaked his knee ligament and he did well to through the second half on Tuesday, and Richard has an ankle problem.
"We do have options, but I'd rather my two main full-backs were available. We'll have to assess everybody right up to the last minute."
With Loft beginning a three-match ban following his red card in midweek, Rob Taylor may come into contention to replace Jones. Although Adams could also switch Adam Yates to left-back and move new signing Anthony Griffith to right-back.
Meanwhile, midfielder Ryan Burge has recovered from the virus that saw him miss out against Bradford.
- Sports & Recreation
- Micky Adams
- Richard Duffy