Usain Bolt's first touch is "like a trampoline" and he will never make it as a footballer, says former Republic of Ireland striker Andy Keogh.
Eight-time Olympic champion Bolt, 32, has been on trial with Australian side Central Coast Mariners since August.
The Australian FA said it is working with the A-League club to help fund a deal for the Jamaican, who retired from athletics last year.
"He's not going to be able to make it," said Perth Glory forward Keogh.
"It's nice to have the attention on the A-League but him playing here, that's not for me," the former Wolves and Millwall player told Off the Ball.
"He's shown a bit of potential but it's a little bit of a kick in the teeth to the professionals that are in the league."
Keogh, who won 30 caps for the Republic, added a potential professional contract for Bolt was "fine from a marketing point of view" but was "farcical" from a football perspective.
"If there's someone who genuinely thinks he'd be a good football addition, I don't think they should be in a position to make those calls," he said.
The Mariners have said it is "unlikely" Bolt would sign a deal without a financial contribution from a "third party".
A Football Federation Australia (FFA) spokesperson told BBC Sport on Wednesday it had now stepped in to try to help.
Mariners boss Mike Mulvey said there was "no update" at a press conference on Friday.
"He's not at training and I'm just concentrating on the lads I have here," he said.
When asked if Bolt had the ability to play professional football, Mulvey replied: "I'll say this one more time - my focus is on the game on Saturday and on the players contracted for the Central Coast Mariners and that is how it should be."
Bolt turned down a two-year deal with Maltese champions Valletta FC this month.