The Hawthorn forward has not played since round 15, when he suffered a hamstring tendon injury against Gold Coast.
With four rounds left before the finals, Rioli is on the verge of joining in ball work at training after a solid program designed to test his body.
"I know the training regime he's going through at the moment, he looks super fit and he's running around about 90 per cent speed, so he's not too far off," football operations manager Chris Fagan told Sportsday.
"He's about to start joining in some ball work - our fitness guys have put him under as much stress as they can to make sure he stands up for the rest of the season and hopefully all things will go well."
Fagan said the Hawks learned more about Rioli with every hamstring complaint he sustained, and had investigated its origin in depth.
Things including family history – Rioli's uncles Maurice Rioli and Michael Long suffered hamstring injuries in their careers – and whether he needed a heel in his boot had been considered.
The Hawks sent Rioli home to Darwin for about a week after the injury, and said they couldn't fault his application to his rehabilitation.
Fagan believes the explosive runner will return with confidence in his body when he does play.
"His attitude is fantastic at the moment and he's just very much looking forward to coming back to play," he said.
"I don't think he has any doubts in his mind he'll be OK when he comes back."
Twitter: @AFL_JenPhelan