Penrith coach Ivan Cleary is confident fullback Dallin Watene-Zelezniak's NRL career is not in jeopardy despite being hospitalised for a collapsed lung.
Watene-Zelezniak, 19, was rushed to hospital on Tuesday night after suffering a relapse of primary spontaneous pneumothorax, a genetic condition that results in the accumulation of air in the space between the lungs and chest cavity.
Cleary admitted the teenager had been experiencing symptoms for the past year and would consult with doctors on a course of action for his rising star, including the possibility of season-ending surgery.
Utility Will Smith will replace Watene-Zelezniak in the line-up against Melbourne at AAMI Park on Friday night, while Cleary also said star hooker James Segeyaro is a slight chance to return from a knee injury.
"(Watene-Zelezniak) got it last year and missed 3-4 weeks so it was a bit worse last year," Cleary said on Thursday.
"It sounds unusual, but apparently for taller, late teenage males, it's not completely unusual.
"It's now a decision on whether it's something we need to surgically fix so it doesn't happen again or he just grows out of it.
"It's not punctured, it just collapses.
"Last year it was about 80 per cent of the lung. This year it was only about 40, so it wasn't as bad."
After initially fearing for Watene-Zelezniak's long-term health, Cleary was optimistic the rare illness wouldn't threaten his career.
"From my understanding, it's obviously serious, but I don't think it's anything that's going to hinder his career," he said.
"Obviously when it happens for the second time, from a layman's point of view you say, 'Gee, this doesn't seem good.'
"But the reports are that it won't affect his career."
The sickness is the latest in a string of setbacks that has hindered Watene-Zelezniak's blossoming career in the NRL.
A beach mishap robbed him of a New Zealand debut in the Four Nations last year, before suspension ruled him out of another Kiwis jumper in the mid-year Test in May.
"He's also packed a fair bit into his young life and young career already as well," Cleary said.
"He's only 19 years old. He's got very strong faith, so I'm sure it'll work out for him.
"He's just going through a few hiccups along the way."
Smith enters the team for just his second appearance of the season, while Cleary also confirmed Segeyaro would fly with the team to Melbourne.
"At this stage he's training pretty well," Cleary said.
"You obviously want him back, it's just coming down to a decision on whether (tomorrow night's) the right time. Next week's game is on the Sunday, but (he's) very close (to a return)."