IF IT wasn't for a 'Sliding Doors' moment as a 16-year-old, untried West Coast tall Matthew Allen might just have finished plying his trade for the Adelaide Strikers in the Big Bash League this season. 

A talented left-handed batsman who loved whacking the ball and describes his crafty left-arm bowling as "mediums, and that's generous", Allen's path diverted towards football shortly after being signed as a Strikers rookie for season three of the BBL.   

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"That was a great experience hanging around the Strikers guys for six weeks and a couple of weeks before the tournament. As a 16-year-old, it was exciting," Allen told AFL.com.au.

"I played in a couple of internals (trials) and was next in actually in a 20/20 to face Shaun Tait at 16. I'm pretty glad I didn't have to go in.  

"I really enjoyed cricket, but when I had stress fractures in my back I leaned towards footy."

While cricket's loss has been football's gain, injuries have remained a blight on Allen's sporting career. 

Since being taken by the Eagles with pick No.62 in the 2015 NAB AFL Draft, the South Australian has barely had a chance to show what he's capable of due to repeat hamstring setbacks, a serious navicular fracture and other niggles.

Now aged 21, Allen is one of just three players from his draft class – including Giants ruckman Matthew Flynn and Adelaide's rookie big man Paul Hunter – still on an AFL list but yet to debut.  

It's a small club Allen hopes to leave in 2019, and a remarkable physical transformation over the past 12 months might finally allow him to do it.

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After arriving at West Coast as a hulking forward, Allen tipped the scales just under 100kg.

Despite converting that "puppy fat" into muscle, the 193cm tall hovered around that mark until last year, when some tough love from coach Adam Simpson motivated him to drop 10kg. 

"I never paid enough attention to what I was weighing. Then Simmo, I suppose, put the hard word on me," Allen said.  

"He wanted me to drop a few kilos, and then last year once I got into a bit of a routine and kept working pretty hard at it, it just kept falling off. 

"The biggest thing I've noticed since I've been this weight, is I haven't been seriously hurt.  

"I've had a few little niggles, but I had stress-related injuries from 16 through to 19 with my feet and my back.

"Since I've lost 10kg it hasn't reared its head again."

A bigger-framed Matthew Allen at training in 2016. Picture: AFL Photos

Allen quickly figured out it wasn't the type of food he ate that was the problem, it was the amount.  

"I always ate quite healthy, but the volume … it was just all I ever knew," he said.  

"I grew up an only child and then went to boarding school, so I never had any shortage of food. It was a bit the same when I first got across here." 

But guidance from mentor Adrian Hickmott and a "slightly light-hearted" spray from former assistant Sam Mitchell during one of their catch-ups helped change those habits.

"Mitch overheard me say what I had for lunch. His neck spun around quicker than anything," Allen said with a laugh.

"I thought I was doing the right thing. Instead of getting a chicken burger like the rest of the boys I got a sandwich and a muffin, and he sprayed me for it.

"He couldn't believe that I had a muffin. Since then I steer clear of them. Between Hick and a few bits of advice from Mitch, I figured out what not to have pretty quickly."  

Track watchers have been stunned by Allen's leaner body shape this summer, and now he is eyeing a rebirth as a hard-running midfielder – the position he grew up playing, and reverted to late last WAFL season.

In the final month of East Perth's campaign, the raking left-footer averaged 21.5 disposals, and put his natural size and strength to good use around stoppages, taking parts of Elliot Yeo and Jack Redden's games and adding it to his own. 

It was a change that might have saved Allen's career at West Coast, and the Mount Gambier product was relieved to sign a one-year extension last October after twice being the Eagles' travelling emergency for away games in his home state.

His housemate and fellow South Australian Luke Partington wasn't so lucky, despite sharing East Perth's club champion award with Allen and ex-Eagle Patrick McGinnity. The harsh reality of AFL hit home only weeks after another of their 2015 draft class, Tom Cole, played in the premiership. 

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"It was tough," Allen said after learning his close mate had been delisted.

"Firstly, we were stoked for Coley, he had a ripper year himself and obviously topped it off with the Granny, so we were super happy for him.  

"Parto taught me a lot really. He had a great attitude towards it. He was playing pretty good footy last year – and he had previous years too – but he wasn't able to force his way into the side.

"But his attitude always was just to knock the door down and eventually they're just going to have to pick you.

"Unfortunately, it didn't work out (for him) but I'll always remember the way he thought about that sort of thing.

"For me, it was just good to get some consistency (in 2018), and for the first genuine time in the back half of last year I started to get close (to a debut). 

"That was the first time I felt like was half a chance.  

"I've waited a bit longer than a few boys from my draft year, but if I can debut it will be worth it."