The Leeds winger Ben Jones-Bishop has been ruled out of action for up to six months while he undergoes treatment on a blood clot affecting his lungs.
Doctors have advised the Super League champions' player to rest for three months, avoiding all contact training.
Jones-Bishop, 24, said: "It is disappointing to miss the start of the season, but I am looking forward and doing everything I can to get back as soon as I can once I am given the all-clear. I am only able to do very light training at the minute and I will have another scan in a couple of weeks to see if I can increase that, but I know I have to avoid contact for three months at least."Reuse content