Tasmania won the toss and elected to bowl on a green-tinged wicket.
WA's bid to win a three-peat of Shield titles was dealt a huge blow on Sunday when star opener Cameron Bancroft crashed his bike.
Bancroft spent a night in hospital and was ruled out of the final with concussion.
WA have selected veteran D'Arcy Short to open alongside captain Sam Whiteman.
But the biggest surprise was the selection of Connolly.
The team is in! 👀— WACA (@WACA_Cricket) Whiteman (c)ShortGoodwinCartwrightHardieInglis (wk)Connolly(Shield debut🚨)ParisStoboGannonRocchiccioliTassie won the toss and will bowl first at the WACA Ground � https://t.co/QNmbpkgzzK#SheffieldShield #WESTISBEST pic.twitter.com/vphPj7TbYoMarch 21, 2024
The 20-year-old spin-bowling allrounder became a cult hero a year ago when he led the Perth Scorchers to victory in the BBL final against Brisbane.
Connolly was set to play in the first Shield game of the season, but those plans were scuppered when he broke a toe while jumping off a boat.
The rising star has been slated to bat at No.7.
Paceman Liam Haskett was the unlucky player to drop out of the squad.
Tasmania have been boosted by the return of star paceman Riley Meredith.
Kieran Elliott was squeezed out of the XI.
Tasmania are aiming to win their first Shield title since 2012/13.
WA: Sam Whiteman (capt), D'Arcy Short, Jayden Goodwin, Hilton Cartwright, Aaron Hardie, Josh Inglis, Cooper Connolly, Joel Paris, Charlie Stobo, Cameron Gannon, Corey Rocchiccioli.
Tasmania: Caleb Jewell, Matthew Wade, Charlie Wakim, Jordan Silk (capt), Jake Doran, Beau Webster, Bradley Hope, Jarrod Freeman, Gabe Bell, Iain Carlisle, Riley Meredith.
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