WEST Coast coach Adam Simpson wants Liam Ryan to become 'Flyin' Ryan' again, but says he will take a patient approach with the premiership forward.

Ryan missed almost all of last year after surgery on his left hamstring following an awkward landing in the round three Western Derby loss to Fremantle.

The 27-year-old suffered another huge blow in January when he tore his right hamstring, leading to another round of surgery.

Ryan made a successful return to the WAFL last month, playing in the unfamiliar role of a rebounding defender, but his performances since making his AFL return a fortnight ago have been underwhelming.

Ryan kicked just one goal from five disposals in a 37-point loss to Gold Coast, and was held goalless from seven disposals in last week's six-point loss to Essendon.

West Coast is in desperate need for Ryan to step up in Sunday's match against Collingwood at Marvel Stadium, especially with leading goalkicker Jake Waterman (concussion), gun midfielder Elliot Yeo (groin) and forward Noah Long (knee) sidelined.

"He's building. He's probably going how I expected him to," Simpson said on Friday. 

"I still think that first game he played, he was genuinely nervous during the week about his body a little bit still.

"We haven't really seen him fly for a mark yet (in a game), have we?

"But he went for a pretty big 'hanger' at training yesterday, so hopefully he can do that this week."

Ryan's electric pace and high-flying marks have been a feature of his 91-game AFL career, earning him the nickname Flyin' Ryan.

Simpson is confident the Ryan of old will be on display once he regains confidence in his body.

"The WAFL games we played him half-back, and he was hitting 32, 33 kilometres an hour," Simpson said.

"We probably haven't seen that speed and agility and flying for those marks just yet (in his AFL games this season), but I'm pretty patient.

"He's been out for a year, two significant injuries, so it's just going to have to take time."

Waterman has kicked 24 goals this season in a breakout campaign, while Yeo has put himself in All-Australian contention after hitting career-best form.

The injured duo will be sorely missed this week.

Collingwood has also been dealt a series of injury blows, with Jamie Elliott (back) the latest player to go down.

He joins a list including Dan McStay (knee), Brody Mihocek (hamstring), Beau McCreery (concussion) and Jordan De Goey (groin) on the sidelines.