Star backman Brad Sheppard has been impressed by West Coast's defensive depth this summer, and says competition for spots is heating up coming into the "gritty" section of pre-season.

While the Eagles have a settled core group down back - led by All Australian trio Jeremy McGovern, Shannon Hurn and Sheppard plus reliable duo Liam Duggan and Tom Barrass - the defensive unit continues to evolve. 

Premiership player Tom Cole, dasher Jackson Nelson and versatile tall Josh Rotham are pushing hard, while emerging youngsters Luke Foley and Harry Edwards have bright futures and recruit Alex Witherden adds a new dimension with his elite foot skills and sharp decision-making. 

“There’s been a few guys knocking at the door – we’ve got a really solid back six – but, there’s probably 10 blokes that could fit into the back six to be honest with you.” Sheppard said.

“Josh Rotham had a good year last year – he’s knocking on the door. Luke Foley’s coming through, you’ve got Alex as well, who’s a new addition.

“We’ve got a good mix of youthfulness and experience.

“You know, for those last couple of spots, it’s going to be who is in good form, and I’m sure, throughout the year, all blokes will get the opportunity.”

Several youngsters are currently vying for a place in the top 22, amongst them ex-Lion Witherden and Edwards, who has grown since last year and now stands at 200cm. 

Witherden, the half-back flanker, was part of a trade deal with Brisbane, which saw West Coast exchange pick 58, and a future third-round selection.

He’ll be eyeing off his debut with the blue and gold – and has been leaning on his experienced teammates to learn the tricks of the trade when it comes to the West Coast outfit.

“Witherden in the backline has slotted in seamlessly," Sheppard said. 

“I think he definitely adds another string to our bow, he’s elite by foot, and makes some really good decisions ball-in-hand, so he definitely is a handy addition for the side.”

Meanwhile, Edwards is also keen to build on his short-lived debut against Geelong when he was accidentally concussed in a collision with Sheppard during the second quarter.

“He’s a great youngster coming through, still growing, think he’s grown three or four centimetres the last six months.” Sheppard said.

“He’s still got a lot of developing within himself but, you see the way he reads the game, he’s going to be a pretty special player.

“Any key position player that’s over 200cm is a real asset to your footy club.

“It’s great he’s learning from the best – you've got ‘Bunga’ (Hurn), ‘Gov’ (McGovern) and ‘TB’ (Barrass).

“It’s good to have young guys that are eager and want to pick your brains, that’s sort of talking about the culture of the footy club, you see all the successful guys in the past.

“You see the group of experience guys that are happy to help out the youngsters, and that’s what you’re seeing here.”

After finishing fifth in the John Worsfold Medal last year, Liam Duggan could be set for more midfield time after a stellar summer to date working largely with the onballers. 

“'Duggo' spent a bit of time in the midfield in the pre-season, he looks good in there," Sheppard said.

“Good to see a mullet running around in midfield – he’s getting a lot of the footy and playing well.

“It’s good for players coming through to have multiple dual roles, because you’ve got to be adaptable in today’s game.”

The cohesive unit now head towards warm-up matches, and the tougher end of the training spectrum, after an extended off-season.

“Onus was on the individual to come back in good shape, because if you came back out of shape, that ramp is probably a bit too great to try and keep up.” Sheppard said.

“It’s been enjoyable, no doubt been hard… training itself elevated in the January period.”

But, to their credit, last year's draftees Isiah Winder, Luke Edwards and Zane Trew have come in eager to impress.

“What they’ve done in the pre-season has been a real highlight… they’ve attacked training," Sheppard said.

“They’ve really been driving the training standards, so couldn’t be prouder at the way they’ve approached the training so far.”