West Coast backman Tom Cole will undergo ankle surgery this pre-season, with the premiership Eagle set to miss the first half of the 2022 season.

The club confirmed on the eve of their practice match against Fremantle that Cole will be sidelined for a lengthy period after suffering damage to his ankle cartilage.

The 24-year-old sustained the injury earlier this week at training, with Eagles football boss Gavin Bell revealing the extent of Cole's injury.

“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,” 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.”

The West Coast half-back has played 78 games for the club since making his debut in 2016, playing a serviceable role in the Eagles' 2018 Grand Final win.

The Bendigo product will add to a growing list of injured Eagles this pre-season, with forward pair Oscar Allen (foot) and Jamie Cripps (pectoral) currently nursing ailments of their own.

The Eagles also confirmed this week that livewire Liam Ryan has entered health and safety protocols and will miss Friday's match against the Dockers at Lathlain Park.

West Coast's attack has also been hampered by the absence of Jack Darling, who is yet to comply with the AFL's mandated vaccine policy.