Hull FC are hoping to retain Martin Aspinwall despite Leigh Centurions announcing his signature on a one-year deal.
The move includes an unusual one-month 'cooling off' period in which Super League clubs can step in.
Hull are yet to activate the clause, although director of rugby Shaun McRae insists they do not want to lose the ex-Castleford, Huddersfield and Wigan man.
"If we can find a way to keep hold of Martin then we will make him an offer to stay at the club," McRae told the Hull Daily Mail.
"We haven't offered him a contract yet, but that doesn't mean we won't. We are trying to work something out so we can keep Martin.
"The key thing is Martin wants to stay at the club and we'd like to keep him, we just have to try and work something out because we only get a certain amount to spend on the salary cap and we've brought new players in and upgraded a few others."