Tom Cole warms up before the round 21 clash between West Coast and Melbourne at Optus Stadium on August 9, 2021. Picture: AFL Photos

WEST Coast premiership defender Tom Cole is set to miss at least half of the Toyota AFL Premiership Season due to an ankle cartilage injury. 

Cole suffered the injury during a competitive training drill on Tuesday and the club has confirmed the 24yo will now undergo surgery.

Meanwhile, forward Liam Ryan will miss Friday's practice match against Fremantle at Mineral Resources Park after entering the AFL's health and safety protocols. Ryan is self-isolating and following government regulations while he receives support from the club.

But the news for Cole is not good, and has added to a turbulent pre-season for the Eagles, who are already planning for a year without the vaccine-hesitant Jack Darling.

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Cole has played 78 career games, including 22 last year and, of course, was half-back in the thrilling 2018 Grand Final.

"It's obviously really disappointing for Tom and the club that he has suffered an injury of this nature so close to games starting and after completing a full pre-season up until this point," West Coast football manager Gavin Bell said.

"We'll continue to assess Tom throughout his rehabilitation, but at this stage we expect he will be sidelined for at least the first half of the season."