IT WAS a sobering thought for Geelong youngster Jed Bews that he missed out on a 2014 finals berth because he wasn't fit enough to run out a full game in the AFL.

The defender, who managed seven games last year, recognised a lack of fitness was a flaw in his game and has set to work this pre-season to ensure it's not an issue going into 2015.

In his post-season review, Chris Scott and the other Geelong coaches made it clear to Bews that he wouldn't get a game if he did not reach the minimum fitness standards.

"They'd watch me and they could tell I was tired," Bews told AFL.com.au.

"They knew that and they've tailored my pre-season accordingly so I've just got to keep working on that."

Under new strength and conditioning coach Scott Murphy, who worked in a similar role when in charge of the Australian Wallabies, the Cats have had a greater focus on longer-based endurance training this pre-season.

Geelong identified that a lack of fitness was a key reason behind its late game lapses and have set about constructing individual programs where players are exposed to a greater training volume.

Bews' program has been designed to meet his needs with a clearer emphasis on improving his aerobic capacity.

The 21-year-old estimates he is running up to 30-plus kilometres each week, which is a "significant step up" from the 2014 pre-season.

Bews, who was drafted by the Cats as a father-son pick at selection No.86 in the 2011 NAB AFL Draft, is desperate to build on the seven games he played in 2014 and lock down a spot in Geelong's vaunted, yet ageing, defence.

Last year, the Cats had confidence to throw some significant challenges Bews' way as he went toe-to-toe with players such as Hayden Ballantyne and Lindsay Thomas.

Learning the way they try to lose their opponents in traffic and a few of their other little tricks was certainly an eye-opener for Bews – the son of club great Andrew – who had spent the first two years of his career at Geelong in the VFL.

"You can watch all the edits you want – and it does help – but until you actually go out and play on them and you experience the things that they do out on the field you don't know what they're going to throw at you," Bews said.

"Blokes like Ballantyne and Thomas – you've always got to be switched on.

"They're sneaky little forwards."

The lack of a small defender, particularly in Geelong's finals losses was noticeable, so a spot is there if Bews does everything in his power to grab it.

Working with guys like Harry Taylor, Corey Enright and Andrew Mackie provides the perfect learning environment for a developing defender such as Bews.

He has the foundations for being the guy entrusted in the small defender role. He's quick off the mark, he's desperate in critical situations and he holds his ground in one-on-one marking contests.

But who better to learn off than Taylor, Enright and Mackie as he seeks to command a spot in Geelong's best 22?

"They're really keen to help out as much as they can which is good. I love playing with those guys," Bews said.

"Harry Taylor's been really good this pre-season, just with his communication and telling me where to run (during match scenarios)."

Bews is well aware the opportunity is there for him to seize. It's up to him, now, as to how badly he wants it.

"Playing a few games last year and having a little taste of it was really good," Bews said.

"Hopefully I can take that next step. Keep improving. That's what the coaches want to see and hopefully I can secure a spot down back. That would be nice."