Four years after Greater Western Sydney scouted him as as one of Canberra's best juniors, Birch will play his first game for Ainslie when the Tricolours take on the defending champion, Queanbeyan Tigers, at Ainslie Oval.

The Giants recruited Birch into their under-18s ranks but chasing his AFL dream came at a cost, with the intense environment draining Birch of his football enthusiasm.

It led to him quitting the game in 2011.

When he decided to make a comeback last year, he was struck down by osteitis pubis and ruled out for the season.

But with his passion back and his injuries behind him, Birch will get his chance to impress against the Tigers.

''I needed to miss footy again [to want to come back] and now I'm just excited to play,'' Birch said.

''I probably should have taken my chance with GWS with both hands, but I didn't.

''I do regret it.

''I was 17 and I didn't really think about it.

''I'd change a few things up now.

''At the moment I'm just enjoying playing, and not putting everything mentally into the game any more is good because you don't stress about it, you enjoy it.''

The 194-centimetre 20-year-old started his school career as a forward.

But his stint with the Giants transformed him to a defender and he will line up at halfback as Ainslie aims to cement its place in the top half of the ladder.

Birch was part of Canberra's first junior contingent to join the AFL's newest club. But that meant driving to Blacktown every weekend for games and training.

It took its toll on the then teenager and he decided he did not want to chase his dream any more.

Ainslie coach Chris Rourke - who re-signed for two more years earlier this week - has been watching Birch's rise since he was a 13-year-old.

''I think he lost his way a bit, but he's a big kid and he's had a good crack at this year,'' Rourke said.

''He's certainly got some good skills and ability … he'll be a work in progress but he's a good lump of a kid.

''His attitude probably wasn't fantastic, he got in the [GWS] program and probably thought it was all going to happen, but it didn't.

''He had loads of talent, but has been up and down … now he's got himself up to standard and it's exciting.''

The Tigers will also inject some youth into their premiership defence with 17-year-old Tim O'Shea to make his debut.

The Tigers are at the top of the ladder and have lost just one game this season, while Ainslie is fifth with three wins from its six games.