Labuschagne, whose last Test century came more than three years and 43 innings ago, is in Australia's squad for the eagerly anticipated series in South Africa in October.
While Labuschagne's place at No.3 hangs by a thread, Hughes is prepared to give the Queenslander some leeway.
The 32-year-old was dropped for Australia's tour of the Caribbean last year, but dominated on return to the Sheffield Shield and deserved to be recalled for last summer's home Ashes.
But the runs still haven't come, averaging just 22.7 in seven Tests since coming back in November in Perth.
"We know at his (Labuschagne's) best, he's a very good player," Hughes told AAP.
"But at the moment, he seems to be in a fairly negative mindset; he's more worried about what can go wrong rather than being positive, scoring runs and occupying the crease.
"He just seems to combat ways that he thinks he's going to get out, and he's finding new ways to get out.
"He's been a very good player for a very long time.
"But if not Marnus at No.3, then who?
"You look at the guys that are playing domestic cricket and pushing for a spot.
"Are they doing enough? And the answer is they're not because they're not getting picked."
Hughes, who will be travelling to South Africa for the three-Test series with a tour group, is excited about the contest ahead for Australia.
He served as selector between 2005 and 2010.
It will be Australia's first Test series in South Africa since the infamous Sandpapergate saga in 2018.
"If Cricket Australia hadn't stepped in, there would have been one- and two-match bans, and they would have kept playing and not an eyebrow raised," Hughes said of the lengthy sanctions to Steve Smith, David Warner and Cameron Bancroft.
"There's always pressure on when you tour overseas.
"South Africa are the World Test Championship holders, so they're in a pretty good space.
"Their bowling's OK, their batting's OK, and you put it together, they just perform well together, and that's what you need.
"I don't think we'll see a rusty Australian side like we saw against Bangladesh."
The 53-Test quick is combining his love for cricket with his skills as a spruiker, after joining forces with Australian Avocados to launch a petition calling for Avo Toast to be declared as the country's official breakfast.
A huge mural with Hughes holding avocado toast has popped up on Rose St in Fitzroy.
13°C