COLLINGWOOD'S Kayle Kirby is in a stable condition in hospital after collapsing behind play during a VFL practice match at the Holden Centre on Saturday night.

He will spend at least another night in hospital, but is reported to be in good spirits.

Speaking after the Collingwood senior team's loss to Greater Western Sydney, coach Nathan Buckley told reporters Kirby's collapse had been due to an irregular heartbeat, but said the club's latest information suggested the forward was "OK".

"Our VFL doctor was over there. He collapsed, it wasn't a contact injury so the details are still coming to light, but it was some form of irregularity in his heartbeat," Buckley said.

"He's in the hospital now and apparently stable. But apart from that, there's no real information to share with you.

"I think the game was stopped for 40 minutes, so it was relatively serious. Talking to the doc, that was all the information they had, but he's going OK at the moment."

Kirby collapsed during the second quarter of the practice match against North Melbourne's VFL team.

According to Collingwood's official Twitter account, Kirby rolled on to his back after collapsing. After being assisted by trainers, he momentarily stood up, before lying back down.

An ambulance then entered the ground to take Kirby to hospital. "He was alert and conscious when he was lifted in on the stretcher," Collingwood said.

Kirby, 19, debuted for Collingwood in round 23 last season, but is yet to play another senior game.