Perth Scorchers skipper Simon Katich and Adelaide Strikers coach Darren Berry gushed in praise of Marsh, who became the Big Bash League's top run-scorer in Adelaide on Thursday night.
Marsh cracked 79 from 60 balls as the Scorchers thumped Adelaide by 98 runs to secure a home semi-final next Wednesday night, probably against the Melbourne Stars.
The Melbourne Renegades will host the other semi-final, against the winner of Saturday night's clash between Hobart Hurricanes and Brisbane Heat.
Marsh's fourth half-century of the T20 tournament took his personal tally to 328 runs, ahead of Renegades skipper Aaron Finch (309 runs) who will make his one-day international debut for Australia in Friday.
Both Katich and Berry say the 29-year-old Marsh is primed to add to his 36 one-day internationals.
"Obviously they (Australian selectors) know what he's capable of," Katich said.
"If he keeps stringing scores together and winning games of cricket, then there is no doubt that he has got the talent to play for Australia.
"If he keeps applying himself the way he is at the moment, then hopefully that will be a reward for him down the track."
Berry's Strikers bowed out of the Big Bash after being unable to contain the left-handed Marsh.
"He's a clean striker of the ball," Berry said of Marsh.
"His skill is undoubtedly good enough to play cricket for Australia.
"I don't know the kid personally and I don't know the other issues but as far as skill and ball striking goes, I think he's an outstanding player."
The "other issues" Berry referred to were Marsh's off-field troubles which played a part in him being dropped from Western Australia's Sheffield Shield team last October.
Marsh and his younger brother Mitch were also dumped from the Scorchers' last pool game in the T20 Champions League last year after an alcohol-fuelled late night out in South Africa.