WHEN Josh Thomas trudged to his customary position in the Collingwood forward line for Saturday night's semi-final against Greater Western Sydney, a familiar face awaited him.

Lined up in the Giants backline and ready to mark his best mate, there was something fitting that it would be Lachie Keeffe standing by his side for much of the match.

If someone had told the pair two years ago that they'd be playing on each other in a crucial September outing at the MCG, neither would have believed such a scenario unfolding.

Back in 2015, both were delisted, handed two-year suspensions and forced to fork out $50,000 worth of fines after testing positive to the banned substance clenbuterol.

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But while both were able to return to a football field at the beginning of last season, it was Saturday night's match that marked a significant moment in their road to redemption.

"It was pretty crazy really," Thomas said.

"Just to be at the MCG, with 80-odd thousand there and playing in a semi-final, you think back to a few years ago running around on soccer ovals trying to keep fit together.

"We've come a long way. I probably didn't think he'd be wearing orange, but it was a cool moment. We shook hands after the game, obviously he was disappointed with the loss, but we also really appreciated how far we've come."

Although their football careers were at a crossroads when the ruling was handed down in August 2015, both were ultimately given a lifeline and redrafted to Collingwood as rookies.

But while Keeffe failed to reclaim his spot in the team and moved to the Giants prior to this season, Thomas remained, becoming a key cog in a new-look Magpies forward line.

He played the final nine games of last year, before featuring in every match this season.

"It's extra rewarding, because a few years ago I wouldn't have thought I'd be here at all," Thomas said.

"It's been a lot of hard work and it hasn't happened overnight. It's been a slow grind, but I've enjoyed this whole year.

"The guys have been awesome to play with and the club is just an enjoyable place to be around. That's all you can ask, to enjoy your footy.

"Obviously it helps when we're winning, but from Monday to Friday, to come in every day has been awesome."

In a significantly smaller Collingwood attack, Thomas has thrived. Combining a role on the forward flank with stints through the midfield, the 26-year-old has turned into one of the club's most prolific goalscorers throughout the season.

One of just seven Pies players to have featured in every game this year, Thomas' 38 goals ranks him third at the club – behind only Jordan De Goey and Will Hoskin-Elliott – and 15th in the competition.

While Thomas had the belief he could turn into a regular in Nathan Buckley's best side, his output this season has exceeded even his expectations.

"It's your goal at the start of the year," Thomas said.

"You've got to believe it yourself, otherwise it's probably not going to happen. But whether I truly thought it would happen, I'm not really sure.

"I've come from a long way back, from having a few years off to last year being in a transition year. I played the last nine games, but I wasn't cemented in the team.

"I was able to just build some momentum over the pre-season and played two JLT Community Series games. I guess it's just built slowly.

"To be in the position I am now, playing every game, I'm absolutely stoked with it."

But Thomas is not done yet. Ahead of a crucial clash against Richmond on Friday night, the diminutive 178cm forward is hoping to power his side to an unlikely Grand Final berth.

Should he and his club do so, he knows exactly who he'll thank first.

"Bucks has always backed me," Thomas said.

"He's always believed in me and my ability. I just had to get some consistency, that was the main thing.

"I think it was a good effort to play nine games last year, but I still had a lot of work in front of me to get into the AFL 22 every week.

"I have a role up at half-forward that I had set for me at the start of the year. I knew where I was going to be playing and I knew that it suited me, with the way I play, so I just gave it my best shot and tried to bring my strengths to the table as often as I could.

"It just worked for me."