If anyone doubted the physical commitment of rugby league's greatest stars, they only needed to watch an exhausted Reece Walsh doubled up and vomiting during Thursday's epic World Cup opener between Australia and New Zealand.
And during the Kangaroos' dramatic 24-22 victory in Sydney, there were plenty of other examples of that commitment - aside from the normal rough and tumble this punishing sport regularly delivers.
New Zealand full-back Kalyn Ponga bravely battled on for 20 minutes with a suspected broken arm before almost having to be scraped off the pitch minutes before hat-trick hero Jack Bostock's winning try for the Kangaroos.
Mitchell Moses initially tried to run off a calf issue before being forced from the field just after the break, while Australia captain Isaah Yeo demonstrated his durability against a powerhouse Kiwis pack, having elected to delay surgery on his injured pectoral muscle just in order play in the tournament.
But understandably, much of the focus was on the star full-backs - Ponga and Walsh.
The Kangaroos number one was playing for the first time for eight weeks after recovering from an ankle injury.
And he delivered a superb try-saving tackle on Ponga during the first-half before scoring a with a sensational 60-metre burst to lay the platform for the Kangaroos' last-gasp victory.
"Walshy was very good tonight having not played for eight weeks," said Australia head coach Kevin Walters.
"I thought he was really good. That try-saving tackle he did is equal to anything that he can do an attack, and then he comes up with a couple of big plays in attack as well.
"He's cramping and vomiting and all sorts of things. He didn't have the energy to kick the goal. He's a chucker [he throws up]. People get nicknames and his nickname is 'Chucker'.
"He's not an endurance athlete. He's a power athlete and he had some big efforts there a couple of times, back-to-back and we've seen him do that before."
Yeo added: "For Reece to come back in a contest like that with some of those plays is a massive effort after not playing for eight weeks. It won't get spoken about enough but it is really hard to do at this level.
"He has just got the ability to just make people miss. I think he made two people miss on the one move but he's just one of those players that can just break a game open, and we probably needed that."
Having finally fulfilled a long-held desire to represent New Zealand, Ponga's night was going sweetly - he scored two tries that included one trademark run from deep and elusive step that left Walsh clutching at air - but it ended on a bitter note.
For one thing, Australia swiped victory from the grasp of Stacey Jones' team. For another, Ponga's futre participation in the World Cup is now in serious doubt.
Speaking after the game, Jones admitted that the Newcastle Knights man would now have medical checks after playing on for a quarter of the contest with an injury sustained in a tackle with Cameron Munster.
"It's a possible fracture of the arm but he's going to go for scans and we're not going to make a call on him right now where he's at," said Jones.
"He had a pretty good game.
"I think he played on for 20 minutes, he toughed it out. It's a tough one. They scored a try and that's when we were told what it possibly was and that he would have to come off.
"He couldn't catch the ball or anything like that, he was in a lot of discomfort."
Should Ponga be ruled out it would be a huge blow to New Zealand's hopes of winning a second World Cup, 18 years on from their first.
