Amiens manager Philippe Hinschberger has named Bongani Zungu's main problem as the player continues his search for first-team action at the Ligue 2 club.
The South Africa international is struggling to play for the Ligue 2 club this season and his last competitive appearance dates back to April 11 in a Scottish Premiership game for Rangers.
Zungu returned from his Rangers loan in June but his physical condition has not improved despite continuous training, according to Hinschberger.
In his latest team update, the French manager disclosed the 29-year-old is not fit to play for the Unicorns who occupy 18th spot in the French second division table.
"Bongani Zungu is not ready at all to play. His issue is that he has a weight problem," Hinschberger was quoted as saying by Daily Record.
"He's been working on this for a while and he's now on more than just one session a day. I've spoken to him about it, but the player himself must take charge.
"We're doing the maximum we can with him. He remains very good with the ball and can read the game, but he still carries weight and does not have the physique of a professional footballer."
The former Rangers midfielder is already in the final 12 months of his contract at the Stade de la Licorne and his lack of competitive outings places his future at risk.
Even on the international scene, Zungu has not been considered for South Africa's 2022 World Cup qualifying campaign.
He endured a tough time at Rangers in the 2020-21 campaign, even though he got a winner's medal for their unbeaten Premiership triumph.
Earlier this year, Zungu was found guilty of breaching coronavirus restrictions in Scotland after attending a party and he was consequently punished by the club and league authorities.