PREMIERSHIP wingman Lewis Jetta looms as West Coast's X-factor during the finals series, and teammate Luke Shuey is tipping the former Swan to fire on the big stage.

Jetta's AFL future looked to be on shaky ground following a disappointing first 18 months at the Eagles.

But the 28-year-old has hit good form in the second half of the season, with his heroics against Adelaide in the final round helping West Coast secure a finals berth.

Jetta's chase-down of Adelaide speedster Charlie Cameron in the final term showed a determination for the cause.

And his dodge-and-weave goal in the dying minutes proved to be the defining moment that helped West Coast edge out Melbourne for eighth spot on percentage.

Jetta missed last year's elimination final loss to the Bulldogs after injuring his calf in the lead-up to the game.

His absence was sorely felt as West Coast was obliterated to the tune of 47 points on their home turf.

Jetta thrives on the big stage, and Shuey expects the 152-game veteran to produce an influential performance in Saturday night's elimination final against the Power at Adelaide Oval.

"The good thing about 'Jetts' is he embraces the big moments," Shuey said of Jetta, who won the 2012 flag with Sydney.

"He played really well in big games for Sydney when he was over there as well.

"He's had success before, so I think he wants to get back to the top.

"He hates losing. I'm just pumped he's hit some good form this year. When he plays well, we generally play well, too."

Shuey also looms as a critical factor in West Coast's hopes of producing an upset win.

West Coast's midfield group have been criticised for being too slow and one-dimensional this season.

Shuey doesn't fall into that category.

The 27-year-old is the team's best line-breaking midfielder and his work in the clinches is crucial.

The Power will have a major advantage in the ruck, where All-Australian Paddy Ryder will go up against Nathan Vardy and Drew Petrie.