Penrith have revealed captain Peter Wallace played without an anterior cruciate ligament in his right knee for two years after the tough hooker confirmed his retirement on Tuesday.
Wallace will make an immediate move into the club's coaching ranks after a shoulder setback prompted him to call time on his 240-game NRL career this week.
However, it's the one final story of Wallace's toughness through ongoing knee issues that will typify his gutsy career.
"It can now be revealed that Peter has played the last two years with no ACL in his knee after his last knee reconstruction actually failed," Penrith general manager Phil Gould said.
"I can also remember him staying on the field for 50 minutes in a game where he tore his ACL.
"He is a tremendously tough individual and his leadership has been wonderful for our club."
That comes despite the 32-year-old almost earning State of Origin selection for NSW last season, before a groin complaint ruled him out.
The revelation only adds to the Wallace story, after he started his career in the halves and became a reliable defender in the middle in recent years.
He infamously played on through a ruptured testicle in just his second State of Origin match in 2008, and played his last of four games for the Blues the following year.
Wallace had hoped to return from a shoulder injury last week against Canberra, before he suffered another setback before his comeback match.
He could only direct traffic from behind the ruck at Panthers training on Monday and texted players afterwards to inform them of his decision.
Wallace will now make a move into coaching at Penrith, after chief executive Brian Fletcher revealed over the summer that processes were already in place to ensure the move.
The club has already put the former NSW State of Origin half through a coaching course and he has worked closely with the Panthers' under-18 and under-20s teams this season.
Wallace has also played a significant role in the development of replacement hooker Sione Katoa, who was a gun youngster in Penrith's development system before taking the reins during Wallace's injuries this year.
"I've been enjoying that," Wallace told AAP two weeks ago in an interview where he was still hopeful he'd return to the playing field.
"I've been doing a little bit of coaching with SG Ball, just a bit of kicking, with (Jersey) Flegg as well."
The veteran hooker debuted with the Panthers in 2005 and had a six-year stint at the Broncos before returning to Penrith.
He was Penrith captain on their run through the finals in 2014 and stepped up to take the role on again this year after Matt Moylan departed the club.