FORMER North Melbourne veteran Drew Petrie and ex-Cat Nathan Vardy hold the key to West Coast's ruck woes after it was revealed Scott Lycett's recovery from knee surgery will take much longer than first thought.

Lycett was originally set to be available for round one after undergoing a PCL reconstruction during the off-season.

But there's a chance Lycett won't be able to return until midway through next season, placing a huge strain on West Coast's ruck stocks.

With Lycett and Nic Naitanui (knee) both injured, journeyman Jonathan Giles is the early favourite to lead the club's ruck division, with new recruits Petrie and Vardy left to fight it out to be his back-up.

Petrie is a 34-year-old forward who has tallied a combined 47 hit-outs over the past three seasons.

Vardy managed just 25 games over seven injury-plagued seasons at the Cats. Since undergoing a knee reconstruction in 2014, Vardy has managed just four AFL games.

Eagles coach Adam Simpson said Lycett hadn't suffered a major setback in his recovery, but the complex nature of the surgery plus his size meant he needed a longer stint on the sidelines.

"It's hard to tell (how long you need to recover) when you have a reconstruction like he did," Simpson said on Wednesday.

"It's not really a hiccup. But when they're the size they are, it just takes a little bit longer.

"We're hoping in the early part of the season (he can return).

"But we want to get it right, along with Nic. So barring any hiccups, we're thinking early to mid part of the season."

Simpson said Naitanui was on track to return from his ACL knee reconstruction as early as round 15 or 16.

Naitanui will have to pass a surgeon's review on December 16 before being given the green light to step up his rehabilitation.

Giles, who spent time on the lists of Port Adelaide, GWS, and Essendon, arrived at West Coast at the end of 2015 as ruck insurance following the departure of Callum Sinclair.

The 28-year-old performed admirably when called upon for four games last season, and his importance has skyrocketed in the wake of serious injuries to Lycett and Naitanui.

"We're going to lean on him for sure. But he needs support," Simpson said.

"We were happy with how he finished the year off. But he can't do it on his own.

"He's more your traditional ruckman, whereas the other two boys (Petrie and Vardy) are forward-ruck type of options.

"I think the spots are all up for grabs across the board."

Simpson said his players had returned in good shape for the start of pre-season.

The fourth-year coach said star recruit Sam Mitchell had fitted in well.

"To get him as a player is magnificent for us on the field," Simpson said of the 34-year-old, who made a shock move away from Hawthorn during the trade period.

"But already I can see what he's doing for our group off the field as well – not only for our kids, but our leaders as well."