The shoulder injury that derailed Mitchell Marsh's international career has proven to be a blessing in disguise, according to former Australia allrounder Shane Watson.

Marsh hasn't played for Australia since he was ruled out of the Border-Gavaskar Trophy Series in India in March with a lingering shoulder injury that required surgery.

As he rehabilitated the clipped wing – his right bowling shoulder – the allrounder focused on his batting, primarily tightening up his defence for the relentless examination of long-form cricket.

The technical tweaks have worked. After he blasted Western Australia to the JLT One-Day Cup title as the state's new captain, Marsh's purple patch with the bat continued into the first-class arena.

In his past six JLT Sheffield Shield knocks, the 26-year-old has registered scores of 95, 28, 141, 11, 43 and 38no to be WA's second-highest run-getter behind Test opener Cameron Bancroft.

Marsh returned to bowling a fortnight ago – ahead of schedule – and picked up two wickets against Queensland. He backed it up with 13 overs at the MCG and has been recalled to the Test squad for the third Magellan Ashes Test at the WACA Ground next Thursday.

QUICK SINGLE Marsh added to Australia's Ashes squad

Watson, who suffered his fair share of injuries throughout his international career, knows what Marsh went through during the off-season and says the dark cloud of injury can have a silver lining.

"He's made the most of a situation that has come about with his shoulder operation," Watson told cricket.com.au.

"It's great to see him make the most of that time he's had to just be able to put all his energies into his batting.

"We've seen the scores that he's made at the start of the season.

Ecstatic Marsh registers Shield century

"That's a great thing about anytime that you have a setback, to be able to turn it into a positive like he has means that he's going to continue to evolve as a cricketer and also as a human being."

As it has with national skipper Steve Smith, the captaincy has lifted Marsh's game to the next level.

Watson describes Marsh as a "natural leader" and says the allrounder is blossoming under WA coach Justin Langer.

"The ease of how he always fits into a group is a testament to the quality of person that he is," Watson said.

"But also having Justin Langer there … he's just an awesome guy let alone as cricket coach.

"To be able to have the support that Mitch Marsh has with Justin Langer there by his side, helping him, supporting him, it's a great combination for a young captain."

2017-18 International Fixtures

Magellan Ashes Series

Australia Test squad: Steve Smith (c), David Warner (vc), Cameron Bancroft, Usman Khawaja, Peter Handscomb, Mitchell Marsh, Shaun Marsh, Tim Paine (wk), Mitchell Starc, Pat Cummins, Nathan Lyon, Josh Hazlewood, Jackson Bird.

England Test squad: Joe Root (c), James Anderson (vc), Moeen Ali, Jonny Bairstow, Jake Ball, Gary Ballance, Stuart Broad, Alastair Cook, Mason Crane, Tom Curran, Ben Foakes, Dawid Malan, Craig Overton, Ben Stokes, Mark Stoneman, James Vince, Chris Woakes.

First Test Australia won by 10 wickets. Scorecard

Second Test Australia won by 120 runs (Day-Night). Scorecard

Third Test WACA Ground, December 14-18. Tickets

Fourth Test MCG, December 26-30. Tickets

Fifth Test SCG, January 4-8 (Pink Test). Tickets

Gillette ODI Series v England

First ODI MCG, January 14. Tickets

Second ODI Gabba, January 19. Tickets

Third ODI SCG, January 21. Tickets

Fourth ODI Adelaide Oval, January 26. Tickets

Fifth ODI Perth Stadium, January 28. Tickets

Prime Minister's XI

PM's XI v England Manuka Oval, February 2. Tickets

Gillette T20 trans-Tasman Tri-Series

First T20I Australia v NZ, SCG, February 3. Tickets

Second T20I – Australia v England, Blundstone Arena, February 7. Tickets

Third T20I – Australia v England, MCG, February 10. Tickets

Fourth T20I – NZ v England, Wellington, February 14

Fifth T20I – NZ v Australia, Eden Park, February 16

Sixth T20I – NZ v England, Seddon Park, February 18

Final – TBC, Eden Park, February 21