"But when he puts his head down he's actually a really good batsman, as we've seen in Shield cricket.
"If he keeps his head switched on and trains really well and focuses on basic things, probably more than the expansive things, then I think that will help him have his consistency."
The critique comes 13 months after Smith publicly slammed Maxwell for "very disrespectful" comments he made about batting below Matthew Wade at Victoria.
Wade was also axed, in favour of Test keeper Tim Paine, in Wednesday's overhaul of the one-day squad.West Australian pacemen Jhye Richardson and AJ Tye are set to make their ODI debuts when Mitchell Starc, Josh Hazlewood and Pat Cummins are rested at some point this month.
Travis Head, Chris Lynn, Mitch Marsh and Marcus Stoinis were the middle-order options preferred ahead of Maxwell, who was crowned Australia's ODI player of the year after a dominant 2015.
Lynn has played just three Big Bash League games since recovering from a shoulder reconstruction.
The Brisbane Heat master blaster, who remains restricted by shoulder and hamstring problems, admitted he felt for Maxwell.
"I know he'll bite down on his mouthguard and really get stuck in, so it won't be too long before he's back," Lynn said.
"His Sheffield Shield (form) has been amazing."
Maxwell enjoyed somewhat of a breakthrough year in 2017.He posted his maiden Test ton in India and was summoned to Brisbane as a reserve batsman for the Ashes series opener after a couple of injury scares.
Maxwell has since produced scores of 278 and 96 in the Sheffield Shield but chairman of selectors Trevor Hohns says his panel wants more "consistency" from the Victorian allrounder.
"In his past 20 matches in this format he has averaged 22 and we need more than that from a player in the side's batting engine room," Hohns said.
"Glenn is still absolutely in our thoughts but for this series we have decided to look again at Chris Lynn."
Wade's international career now appears over. Paine will soon be Australia's incumbent keeper in all three formats.
Australia's ODI squad: David Warner, Aaron Finch, Steve Smith (capt), Mitch Marsh, Marcus Stoinis, Travis Head, Chris Lynn, Tim Paine, Pat Cummins, Mitchell Starc, Josh Hazlewood, Andrew Tye, Adam Zampa, Jhye Richardson.
- AAP