Hull FC forward Dean Hadley is returning home from England Knights' tour of Papua New Guinea due to illness.
The 26-year-old back rower was in the team that gained a 16-12 win over the Kumuls last weekend and was in line to make a second appearance in Port Moresby on Saturday.
Hadley said: "Over the last couple of days I've been in hospital and had a bit of an illness but I'm out of hospital now and I'm all good.
"I've been told I can't play this weekend and I can't train either. I just felt it was the best decision for me.
"The last couple of weeks has been great, the experience has been great, I just wish the boys the very best for Saturday - I'm sure they'll get the job done."
Knights head coach Paul Anderson said: "We're obviously disappointed because he's a quality player and a quality person but we have to take medical advice.
"He spent a night in a Papua New Guinea hospital, the medical care was first class, not just our staff but the staff at the hospital have looked after him.
"I think it's a credit to him that he doesn't want to be a distraction to the boys, he wants to sort himself out medically.
"He's been a consummate professional. I was fortunate enough to spend last two weeks with him in camp and I feel privileged to work with him."