Hardwick slammed as "un-Australian" the attack on Martin, one of the AFL's most exciting young talents.
An agitated Hardwick fronted a media conference in Melbourne on Friday ahead of a Tigers intra-club practice game.
He dismissed as "unsubstantiated rumours" claims that Martin could be embroiled in Australian sports widespread investigation from national crime authorites into alleged illegal behaviour.
AFL clubs have been informed by Australian Crime Commission officials that at least another player is under investigation for connections with underworld figures.
The player and his club have not been named by AFL or ACC authorities.
Reluctance by officials to release any details of further allegations and investigative intentions continues to taint the entire league and seemingly annoyed Hardwick.
Martin, just 21, was one of Richmond's top performers in last week's exhibition match against an official AFL Ingenous All-Stars team in Alice Springs.
"He's a resilient individual but all we can deal in is the facts," Hardwick said.
"He's training very, very well. We're pleased with the way that he's going.
"You've only got to look at his form versus the All-Stars last week.
"His disposals probably weren't to the level that we expect but he's one our better players.
Hardwick said the fact that rumours were swirling around Martin without any substance was something foreign to Australians.
"It's disappointing - social media, it's un-Australian," he said.
"It's just whingeing, whining. I can't stand it.'
Hardwick said Martin, who was suspended for two games last year by the Tigers for missing a training session after taking a sleeping pill, was abiding by team rules.
"All we can deal with is the facts," he said.
"He's training very, very well and he's going to be a very, very good player for us this year."
Hardwick praised his outfits pre-season, despite a 50-point loss to the All-Stars unit a week ago.
"It's been a lot better," Hardwick said
"The training age of our team has improved so that means we can get more training into our guys.
"We've had a new fitness regime come in and we've been really impressed with that one.
"We've been pleased with what we've been able to put on the track.
"The thing that has been noticeable is that the boys can handle more work, compared to last year."
With assistance from AAP