Tidser, who signed from Morton in the summer, has joined Scottish Premiership side Ross County on loan after making 16 appearances for the Millers.
The club have also confirmed that Lionel Ainsworth has extended his loan with Motherwell until the end of the season.
Tidser's departure follows David Worrall's temporary switch to Oldham and the early release of defender Pablo Mills, who has since signed for Bury.
Striker Kayode Odejayi extended his stay at Accrington earlier in the week, while negotiations are ongoing for a permanent move to Bury for Daniel Nardiello.
David Noble is set to extend his stay at League Two side Cheltenham while on-loan striker Matt Tubbs has returned to parent club Bournemouth after his deal expired.