Another League One club is said to have joined the race to sign Lee Novak.
Reports in South London suggest that Charlton Athletic are keen to snap up the striker, who became a free agent when released by Birmingham at the end of last season.
Novak was Chesterfield’s top goalscorer while on a season-long loan, hitting the net 15 times for the struggling Spireites.
Russell Slade may have to do battle with ex Chesterfield boss Paul Cook, with the Pompey boss also reportedly determined to sign Novak.
Both Sheffield United and Shrewsbury were linked with moves for the striker earlier in the summer but those rumours have now been quashed.
Chesterfield’s own interest appears to have diminished, with a return to the Proact looking increasingly unlikely for the fan favourite.