Skysports.com understand Carlisle duo Michael Bridges and Karl Hawley have turned down new deals at the club.
The League One new boys have held talks with the pair about contract extensions with both players having just a year to run on their present deals.
Carlisle are hoping to tie down the duo to new long-term deals, but talks are thought to have reached an impasse.
The strike pair played an instrumental role in the club's promotion last season, scoring the goals to help them win League Two.
The Cumbrians are thought to have offered Bridges a new deal on significantly lower terms than he was on previously.
Bridges is believed to be unhappy with the offer and is thought to be considering his future.
Darlington have had a bid rejected for the former Sunderland ace and a number of Championship clubs are believed to keeping tabs on his situation at Brunton Park.
Several sides are also thought to be watching Hawley following his exploits last season.
The news of their contract situation could alert a number of clubs who may try and lure the pair away from Brunton Park.