Hardaker, 22, cited personal reasons for his withdrawal, and was reprimanded by his club, as well as being put through his paces with an immediate return to pre-season training.
Head Coach Brian McDermott said: “Zak has been through some tough times, of his own making, but his attitude since then has been first rate. I can not praise him enough for how he has dealt with that lesson and the determination that he has shown to put things right.
“As a club, we took action against him and he has never once complained or whinged about the situation. At the end of a long season, he had a holiday booked but he was told to cancel that and start pre-season training. Mentally that is a challenge for anyone, but especially a young lad, and he has dealt with it well.”
Hardaker will line-up alongside Liam Sutcliffe in the halves for the game at Headingley, which kicks off at 11.30am.