Tigers boss Phil Brown has admitted Hull are considering the recent offer for Sam Ricketts.
It is believed that Portsmouth have bid for the Wales international defender.
Brown said: 'We're assessing it on its merits in a professional manner.
'Sam has another year left on his contract and if the lad wants to stay he has to show it in the opening games of the season.
'It's a balancing act and he's getting on with pre-season in a professional manner.
'We've had one firm (offer) and another (club) showing interest.'