The departures will help clear the decks for incomings set to be announced soon by the Tigers as they continue the team rebuilding started 12 months ago.
Australian half-back Miller has been the subject of speculation about a possible move to Huddersfield Giants and is now clear to do so after Castleford released him from the final year of his contract.
He had signed a three-year deal when he moved across from Wakefield Trinity ahead of the 2023 Betfred Super League campaign.
Also released from the last year of his deal is former Man of Steel Paul McShane, who, as has previously been reported, is retiring from full-time rugby league.
Lebanon international second-rower El-Zakhem, Papua New Guinea international Nixon Putt and another forward, Daniel Hindmarsh, are all leaving midway through a two-year deal.
Back-rowers Brad Martin and Luis Johnson are out of contract and free to find clubs, while centre Corey Hall, who was loaned from Hull KR, has joined Wakefield for 2025 and prop Samy Kibula is not being retained after his one-year deal has ended.
Director of rugby operations Danny Wilson explained: “We’ve got a turnover of nine players and it happens at the end of every season with us and other clubs
“Like everyone, we’re trying to improve and move forward as a club.
“Some of these players have had some great games for Castleford, so we want to thank them personally for everything they’ve done for Castleford Tigers on and off the field and we wish them all the best in their future endeavours, whether that be retirement or moving to another club.
“We have an exciting couple of months ahead as we continue to look into the market. “We as a club have a couple of signings confirmed and we can’t wait to share these with you in the coming weeks.”
