Sky Sports understands Gillingham need to offload some players before they can offer Deon Burton a new deal.
Burton's contract at Priestfield expires next month after he initially signed a one-year deal last summer.
The 36-year-old impressed at Gillingham last season and helped the club to win promotion to League One after scoring 13 goals in 31 starts.
Gills boss Martin Allen is keen to keep hold of the former Portsmouth and Charlton striker, and wants to offer him a new deal.
However, Allen needs to trim his squad and boost his budget in a bid to offer Burton a new contract at the club.
Burton's adviser, Darryl Powell, confirmed Allen wants to keep the former Jamaica international and is working on ways to secure his future.
"Martin is really keen to keep Deon at Gillingham and he wants him to sign a new deal," Powell told Sky Sports.
"Martin knows he needs to save some money by offloading some players to keep Deon and he is working on that.
"Deon has enjoyed his time at Gillingam and would be happy to sign a new deal."