Grimsby Town will look to bring in new central defenders in January after former skipper Darran Kempson left the club by mutual consent.
Kempson, 27, had six months remaining on his two-year contract, but had fallen out of favour at Blundell Park.
Club joint manager Rob Scott declined to comment on suggestions of a training ground bust-up between Kempson and another player.
Kempson was a regular last season after signing from Accrington Stanley.
Scott told the Grimsby Evening Telegraph: "There are always rumours of incidents and that goes on.
"From mine and [joint manager] Paul Hurst's perspective, we've come to the conclusion that 'Kemps' wouldn't be involved in the starting XI.
"For the sake of his career, he probably needs to get playing again - it hasn't been the best of seasons for him so far. He's a genuine lad and I have nothing but praise for the way he tries to put things right."
Kempson lost his place after suffering an ankle injury and has been unable to regain it.