You could be forgiven for thinking Gold Coast defender Sam Collins has mixed emotions ahead of Sunday's match against former club Fremantle.

After 14 games for the Dockers across 2016 and 2017, Collins was cut, forcing him to VFL club Werribee to rebuild his career.

Still just 24, Collins was picked up by the Suns as part of the AFL's special assistance package at the end of last season.

Even quicker than his AFL career was back on track, Collins has become an integral member of Gold Coast's defensive unit following the season-ending ACL injury to Rory Thompson.

Ahead of playing Ross Lyon's men at Metricon Stadium on Sunday, Collins told he had no ill feelings towards Fremantle.

"When you look at it, they gave me the flick but no-one picked me up, so it was on me to prove I'm worth another crack and Gold Coast took a punt on me," he said.

"I want to repay that favour. I don't need to do anything special.

"I will be a bit nervous I suppose because I'm playing against guys I used to play with, but I'm really excited for it."

Collins is forming part of an undersized backline alongside 100-gamer Jack Hombsch and impressive second-year defender Charlie Ballard; all three stand 195cm or less.

What Collins lacks in height, he makes up for with strength and ability to aerobically run better than most players his size.

He was solid against St Kilda last week, and his final play contest against Jack Newnes, where both players collided while contesting the ball, was shown in Gold Coast's review as a standard it wants to uphold.

The incident left Collins slightly dazed, and he needed to pass the concussion protocol all week.

The ever-pleasant, often-smiling defender said Thompson's injury had opened the door for him, and now he wanted to slam it shut.

"When he went down it probably increased my chances of playing," Collins said.

"I'm just happy to go out there, play as best as I can and try and replicate him. It's a big hole to fill.

"Coming here I didn't know where I was, but I just put my head down.

"Until someone can knock me off the perch, I'm going to keep trying to build on things and try to be consistent with my performance.

"It was really unfortunate for Rory, but I feel as though myself, 'Hombschy' and Charlie, and whoever else, will be able to work together."