Aidy Boothroyd remains hopeful he can lure Clarke Carlisle to Northampton.
The Cobblers boss took the experienced defender on loan from Burnley last season and the 32-year-old is now out of contract.
Boothroyd told BBC Radio Northampton: "I think there is a chance [of him signing towards the end of pre-season].
"There are a lot of different variables when you are dealing with Clarke and there have not been any ultimatums."
He added: "When you try and bring players in, I think you have to treat every individual as a separate case.
"As we are going along, things will evolve naturally. I think we do need a centre-half."