Dallin Watene-Zelezniak is almost back to 100 per cent fitness after his dramatic health scare last NRL season, but concedes it is the greater mental demons he will have to overcome as his recovery from a collapsed lung continues.
Watene-Zelezniak extended his contract with the Panthers for one year on Tuesday until the end of the 2017 season.
After his 2016 season was cut short in July by the injury, which likely came from a knock during a game or training, Watene-Zelezniak said he had been assured by doctors the freak incident was unlikely to happen again and end his career.
"I'm fully fit and ready to go, it is more mentally getting around the fact of not covering it up," Watene-Zelezniak said at Penrith pre-season training on Tuesday.
"The fact I couldn't breathe was pretty scary I didn't know what was happening.
"At first it was a scare, but I have been lucky and I'm back doing something that I love.
"The specialist said I'm 100 per cent and that it shouldn't happen again; he is a specialist for a reason.
"It has gone well. I have had a couple of months for the lung to heal and get back to where I was last year, and I am getting close to that."
The 20-year-old said he only signed on with Penrith for another year to bring out the best in himself.
"It's awesome to stay at a club I have been with since I was 12," he said.
"My manager and I decided we would just go for one year, it was more a motivation thing for me, instead of signing for four years and getting comfortable I wanted to challenge myself."
Young playmaker Nathan Cleary also re-signed with the Panthers for three more seasons on Tuesday.
The son of ex-coach Ivan Cleary, he said his father's sacking from Penrith had made his decision to stay at the club easier.
"It's made it easier for me to carve my own path and follow the direction I want to go without having people speculate about the influence of my dad," the 17-year-old said.
"It's an awesome feeling to get the deal done so I can focus on preparing myself for the upcoming season."