Queensland State of Origin forward Ashley Harrison is in serious doubt for Friday night’s NRL derby showdown with Brisbane after breaking down at training on Thursday.

Harrison, who missed the series-deciding third Origin game earlier this month with a fractured big toe and hasn’t played since, lasted less than 20 minutes before quitting the Titans’ final session on the Gold Coast.

Coach John Cartwright virtually ruled him out on the spot but will delay making it official until Friday morning.

“It didn’t look good. He’s pretty honest, Harro (Harrison). If he was right to play, he would have finished the session,” said Cartwright.

“I’d say he’ll be out tomorrow.”

Cartwright said while it would have been great to have Harrison on deck against Brisbane, it “wouldn’t get us down”.

“There’s nothing we can do about it, we’ll have a chat about it and make some decisions in the morning.”