Ben Haim is likely to consider his position before deciding his future

Henrik Pedersen, Quinton Fortune, David Thompson and Cesar Martin will be allowed to leave the club when their existing contracts expire in June.

The deals of defenders Ben Haim and Augustyn also run out this summer but Lee hopes to persuade them to stay.

Centre-back Ben Haim had been linked with a move to Chelsea in January 2007.

Pedersen joined the club in 2001 from Silkeborg and has scored 22 goals in 143 appearances in his time with the Trotters.

Fortune struggled with injuries following his move from Manchester United last summer while Thompson also battled for match fitness after moving from Portsmouth in January.