Since Sharks skipper Cameron McInnes' season-ending injury a month ago, Colquhoun has held his own as the team's No.13 and has retained his starting spot for Saturday's semi-final away to minor premiers Canberra.
A win over the Raiders would propel Craig Fitzgibbon's side into a preliminary final showdown against the Storm in Melbourne.
Many pundits would cast doubt over the Sharks' hopes of getting past Canberra and Melbourne in successive weeks, but Wollongong-born Colquhoun is used to having the odds stacked against him.Â
Colquhoun overcame two stress fractures in his right foot and an anterior cruciate ligament injury before turning 23 last year.
And the forward only landed on Cronulla's radar after being overlooked by St George Illawarra as a junior because he refused to take no for an answer.
"I was probably a little bit too small, not fast enough and not strong enough," Colquhoun told AAP.
"As a teenager everyone shot up before I did and I didn't really enjoy footy too much, I found it hard because it was like I was playing against men but that experience allowed me to knuckle down on my skill.
"I was lucky the Sharks had an open trial, and Blayke Brailey's dad, (Sharks recruiter) Glenn, spotted me.
"In those trials you have to submit your name and all your representative history on it and my piece of paper had nothing, just my name."
Colquhoun filled in - out of position at centre - and did so well Brailey invited him back for a second trial where he got the chance to showcase his ability as a forward.
Colquhoun's teammates rate competitiveness as his strongest trait, a fact underlined by the fact he won the Sharks' recent in-house table tennis tournament.
"At the start I was shocking but kept grinding away and beat Will Kennedy, who everyone will say is the club's best player, in the semi-finals," Colquhoun said.
"That was pretty much like the grand final, then I faced Nicho (Hynes) and I'm sure he wouldn't want to talk about how that went for him."
Colquhoun watched with interest as the Green Machine and Brisbane went to the extra-time in last Sunday's qualifying final and is ready to go the distance with Canberra's intimidating forward pack.
"I've never played a game (that's gone for 94 minutes) but if it does, I'll be jumping out of my skin," Colquhoun said.
"We are going to have to be on from the start because you can't give them a sniff."
