A year after his cricket career looked on the skids, Shaun Marsh will captain Western Australia while pressing for a Test recall.

Warriors coach Justin Langer was full of praise for the explosive left-hand batsman after Marsh showed strong form in the domestic one-day competition.

Now Marsh must build on that in the Sheffield Shield, starting this Wednesday when WA play Victoria at the MCG.

But regardless of whether Marsh can break into the Test team for this summer’s Ashes series, his stand-in captaincy is already a significant milestone.

Off-field misbehaviour, injury and poor form had combined to take Marsh well off the national radar late last year.

“It is a huge deal from where he was probably last November or December,” Langer told AAP.

“He probably hit rock-bottom, to be honest, and sometimes a person has to get to there to really recognise where he wants to go with his life and career.

“So for him to be named as captain is a great achievement for him and a great credit to him.”

While Marsh had his issues, Langer always had faith that the batsman could make the most of his talent.

“He’s such a good person, Shaun Marsh,” he said.

“He’s made a lot of mistakes, but one thing I’ve known about life is fools don’t learn by their mistakes.

“He was probably going down that path, but we gave him some pretty strict boundaries and he’s been meticulous in everything he’s done.”

Langer and Marsh’s brother Mitch said Shaun had taken on more leadership responsibility within the WA squad.

“Shaun’s a quiet person, but over the past 18 months, he’s taken on that leadership role with such a young squad that we have now,” Mitch said.

“All of us young guys certainly look up to what he does off the field.

“And on the field, when he’s not injured, we all have a great amount of respect for him.”

Langer said Ashton Agar, who had split webbing in his hand during the domestic one-day series, would definitely play against Victoria while Will Bosisto and Cameron Bancroft will make their Shield debuts.