Former loanee Caolan Lavery has backed the Spireites for play-off success.
The Sheffield Wednesday striker spent a month on loan at the Proact earlier this year, scoring three goals in eight appearances.
And he says he saw enough in that time to make him confident Chesterfield can mount a strong push for Championship football.
“I definitely think they are good enough to do it,” Lavery told the Star.
“There are some very good players and the club and Paul Cook has done really well with what he’s done with them this season.
“They play exciting, attacking football and they don’t fear anyone.
“They’ve got a fantastic chance to win promotion and they’ll give anyone a game in the play-offs.
“I had a great time there and I’m very grateful for them giving me the opportunity to get back playing games and scoring goals.
“I wish them all the best and I’d love to be playing against them next season.”
Chesterfield could secure a play-off spot this afternoon if they win at Oldham Athletic and Rochdale lose away at Gillingham.