Mitch Marsh says there's one key factor behind his stunning batting revival.

"To be brutally honest, I have just practised hitting sixes," Marsh said after peeling off a century for Western Australia against South Australia in Wednesday's one-dayer.

"And that is all I really did before I went away and it seemed to work for me so I will keep doing that."

Marsh's training tactic paid dividends on Australia's Twenty20 tours of the West Indies and Bangladesh in July and August.

The often maligned Marsh, promoted to No.3 in the batting order, struck four half-centuries, boasted a strike-rate of 124 in 10 digs, and was Australia's best-performed batsman on those tours.

On Wednesday, he cracked 111 as WA trounced the Redbacks by 78 runs in the first match of the fresh domestic cricket season.

But on Thursday, Marsh will return to Perth instead of playing in the WA-SA Sheffield Shield game starting the following day in Adelaide.

And he says he'll continue hitting sixes in a training block ahead of Australia's departure for the T20 World Cup in the United Arab Emirates starting October 17.

Marsh is keen on retaining the first-drop slot despite Australia's star batsman and usual No.3 Steve Smith returning for the World Cup.

"I'm hopeful to be up there but we have got so many good players," Marsh said.

"Steve Smith has held that role for a fair while now and he's a fair player that guy.

"Whatever role I get, whether it's batting at number three or floating through that middle order ... I am just going to be really clear on my role and do it to the best of my ability and hopefully that helps Australia win games of cricket."