Rockhampton

The 34-year-old — one half of Busby Marou — was playing touch football in Rockhampton last week when he started feeling light-headed.

"I just thought I was puffed and unfit," he said.

"There was tightening across my chest ... it was all the things I had read about, all the signs.

"I still didn't think that was it, but I had a good crew around me that got me to the hospital."

Troubled by an achilles tendinitis injury that he picked up at the Downer NRL Auckland Nines, Marshall trained strongly at Brisbane's captain's run on Thursday morning but has not been able to force his way into Brisbane's best 17.

Alex Glenn has one more appointment with the doctor before he is cleared from the concussion he suffered against the Sharks last week but Broncos officials are very confident that he will be passed fit to meet the Cowboys.