Former Spireites and Millers defender Gregor Robertson has joined Crewe Alexandra on a two-year deal.
The former Scottish U21 international was released by Chesterfield in the summer and could be joined at Gresty Road by Jamie Lowry.
The utility man had a loan spell with Crewe last season and has been offered a deal but a few medical issues have halted the progress of the move.
Jonathan Grounds, borrowed by John Sheridan from Middlesbrough last term, has joined Oldham Athletic on a two-year contract.
Chesterfield coach Mark Crossley has been the target of speculation about his future.
Newly appointed Birmingham City manager Lee Clark struck up a friendship with the ex-Owls keeper when the two were colleagues at Fulham and it is possible that Crossley could be moving to St Andrews as part of their new back-room team.
The recruitment of Sam Togwell at the beginning of the week looks as though it could end Spireites’ acquisition trail unless any current players move out.
The likes of Sam Hird and Marc Richards have taken up a significant chunk of the playing budget so Sheridan may have to work with a squad of 21 rather than one more than that as was expected.