RICHMOND is confident forward Ben Griffiths can return this season, despite the uncertainty surrounding his recovery from concussion issues.

Griffiths has been sidelined indefinitely since late April after suffering his second head knock this season with an elbow to the head in the VFL.

The 25-year-old suffered his first concussion of the season in round two, with teammate Jack Riewoldt saying at the time Griffiths had suffered more than five head knocks through his career.

Richmond has been unclear on Griffiths' immediate playing future over the past month, but assistant coach Justin Leppitsch was hopeful the key forward would return this season.

"He's back training now and taking some sort of knocks, obviously not to the head but to the side and things like that," Leppitsch told Triple M.

"He's building his confidence in that area. 

"It's obviously such an unknown isn't it, concussion and what happens inside the brain.

"So we're obviously very mindful of his health as well."

Griffiths and those around him have been treating the issue like a long-term injury, but there has been no suggestion of retirement from the contracted tall.

The Tigers have put his return to the game in the hands of medical experts, taking an ultra-conservative approach with his workload in training.

Leppitsch said the uncertainty around concussion meant it was impossible to guarantee a return for the No.19 pick in the 2009 NAB AFL Draft.

"I obviously had a situation with Justin Clarke last year when I was at Brisbane and it was a really sad time," Leppitsch said.

"To watch a boy at the age of 21 lose his career, that was a really hard thing to handle.

"We all hope that it doesn't [end Griffiths' career], but I don't think we can categorically say either. There's so much unknown with the injury."