McMeekan is not out of contract. His current deal has another season to run after this one.
Hardaker is not out of contract. He is on loan at Castleford and is technically contracted to Leeds next year. However, Cas have a option to purchase him for a fee already agreed.
Springer isn't out of contract either, he signed a new deal earlier this season.
The only players out of contract at Cas are Lynch (retiring), Chase (we have already said he won't be getting a deal next year) and Monaghan (who has actually looked better this year than he did in 2016)