But Martin hopes the 27-year-old will stay with the Shrimpers and is planning talks to discuss a new deal.
"With just two remaining games hopefully we can have those formal discussions with Peter and his agent soon," Martin told the club's official website.
"I have been unequivocal and consistent and I hope once again I have made it clear that I would like him to stay at Southend.
"(Manager) Steve Tilson has reiterated to Peter that we would like to talk to him about a new contract. Whether terms can be agreed I do not know, but I do hope so."