Earlier, the Steve Smith-led side, who played with an unchanged Playing XI in the first two Tests, took a 2-0 lead in the ongoing Ashes series after clinching a massive win by 120 runs over England in the second match at the Adelaide Oval.
However, prior to the remaining matches, Marsh has been tipped for a recall in the Test squad, with Gillespie suggesting that a fourth bowler who could support the front-line quicks in the team could be vital.
"I said after the first two Test matches the Australians may add someone to their squad, possibly an all-rounder because they'll feel the surfaces in Perth, Melbourne and Sydney are three very good batting surfaces," cricket.com.au quoted Gillespie as saying.
"And the three big hairy quicks are going to need a little bit of support. So don't be surprised if a Mitchell Marsh or that type player comes into the equation," the former quick added.
The 26-year-old underwent full shoulder reconstruction after sustaining an injury during Australia's tour of India in March and he hasn't played a Test match since then.
However, Marsh made a return much before expectations during Western Australia's match against Queensland in their Sheffield Shield game at the WACA Ground late last month, when he finished with the figures of two for 49.
While he also notched a century during that match, scoring a knock of 141 in the first innings, Marsh also smashed 43 and 38 not out during Western Australia's drawn match against Victoria at the Melbourne Cricket Ground (MCG) this week.
As a result, his recent rich vein of form makes him front-runner to join his brother, Shaun Marsh, in Australia's Ashes squad for final three Tests.
Australia are currently leading the five-match series 2-0 after clinching a massive win by 120 runs in the second Test against England at the Adelaide Oval. (ANI)