Queensland Origin forward Cotter will be a vital cog in North Queensland's pack in the NRL preliminary final clash with Parramatta in Townsville on Friday night.
Cowboys strength and conditioning coach Ash Graham had the same role with the under 20s when Cotter ruptured his ACL twice as teenager and missed most of the 2016, 2017 and 2018 seasons.
"Reubs was 18 when he played his first game of under 20s and got man of the match. His second game he did his ACL," Graham told AAP.
"He did all his rehab and redid it filling in for first grade in an opposed session.
"His second recovery was much longer because he had to have a bone graft, and then his second knee reconstruction after that.
"Most kids at that age, you wouldn't be surprised if they'd give it up but Reubs is so driven.
"It speaks so much about his character that he has come back from it. Plenty of guys are physically strong, but mentally is where he is ahead of most."
Cotter said he would forever be grateful to the Cowboys for believing in him through his injury ordeal.
"The Cowboys supported me the whole way through the recovery. Despite being injured for three years, they still re-signed me," Cotter told AAP.
"Ash Graham ran all my recovery and was a huge help.
"I was young at the time and knew I had age on my side. I knew if I knuckled down I would get back to playing.
"That's why it is great to finally be playing in a prelim final. I am really excited for Friday night."
The way Cotter throws himself into the fray is reminiscent of the whole-hearted approach of 2003 Penrith premiership winner Martin Lang.
"And that's the way he trains," Graham said.
"The way he plays on the field is the way he approaches everything he does, whether it be in the gym or cardio. He is very competitive and ruthless in what he does."
Cotter made his Maroons debut in Origin this year and coach Todd Payten said he "wouldn't look out of place" with the Kangaroos at the Rugby League World Cup.
"He makes us a better team. He's a tough competitor," Payten said.
"He's had to do things the hard way with his body to get to this point in his career and I'm just happy that he's able to get some continuity in his footy.
"You saw what he did. He played 80 minutes in Darwin (against the Eels) and that was hot. He played 80 minutes in Origin. That was quick. And he's going to play some big minutes tomorrow. He's really important for us."
10°C