Fresh concerns surround AFL concussion protocols after North Melbourne ruckman Tristan Xerri played on for 10 minutes following an “unusual collapse” on Thursday night.

The 26-year-old simply dropped the ball and fell to the turf after copping a glancing blow early in the fourth quarter of the Kangaroos’ 13.7 (85) to 20.14 (134) loss to the Western Bulldogs at Marvel Stadium.

But Xerri was not immediately taken from the field, sparking renewed criticism of the process for head injury assessments nearly two months on from the high-profile Lachie Schultz controversy.

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Brian Taylor spotted the “little glancing blow” from Bulldogs star Sam Darcy to the helmeted head of Xerri even before watching replays that showed forearm contact.

“He just dropped,” Brian Taylor said in live commentary on Channel 7.

“It was unusual, so this is going to be big news as well for the North Melbourne ruckman.

“He gets back to his feet. The umpires are on to this. Will they stop the game and order that he goes off?

“It was an unusual collapse, a glancing blow underneath. And he just collapsed.”

Xerri appeared to wave off an approach from a North trainer on the field while club doctors began to view replays on a sideline monitor.

“Still wobbly and he’s still out there. They’ve got to get him off,” Port Adelaide premiership player Kane Cornes said.

Hawthorn great Luke Hodge noted Xerri was “holding his head in the middle of the ground” as play continued.

Xerri was checked on by opposite number Tim English after the incident, but the North ruck still remained in the game.

“We can’t forget this year the AFL introduced rules where the ARC (review centre) can intervene and stop the game to bring the player off,” boundary rider Mitch Cleary said.

“It’s surprising he’s still out there.”

Cornes was concerned by the delay.

“Why is he still out there? What are we doing? Go out there, a goal has been kicked — get him off the ground and check him,” he said.

Taylor replied: “How can we see it and they not? It’s bizarre.”

Hamish McLachlan added: “Surely this is exactly what it’s there for, moments like this right now. (North doctors are) looking at what we’ve seen. Haven’t they seen enough at this point to say ‘let’s just get things checked out?’”

Footage then showed another Bulldogs player approach Xerri.

“Pretty odd scenes, I’ve got to say — Tom Liberatore checking on the welfare of Tristan Xerri,” McLachlan said.

Liberatore later told Channel 7 there is now a code among players, saying he remains grateful for opponents Darcy Parish and Conor Nash checking on him following two concussions last year that threatened his career.

Meanwhile, Xerri finally left the field roughly 10 minutes after the incident and went straight down to the rooms.

North doctors were still reviewing footage on the sideline monitor after the final siren.

“The AFL should look into the management of it,” Cornes said after the match.

The league has previously come down hard on Port Adelaide for a breach of concussion protocols, handing out a $100,000 fine ($50,000 suspended) in 2023.

Port teammates Lachie Jones and Aliir Aliir clashed heads and both underwent initial assessments but only Jones was sent for a formal concussion test.

7NEWS is not suggesting North Melbourne breached concussion protocols with Xerri.

But in another concern for the Kangaroos on Thursday night, the incident followed star midfielder Luke Davies-Uniacke suffering a concussion in the first quarter.

He was immediately substituted out of the game.

Meanwhile, Bulldogs star Ed Richards played out the match despite leaving the field in agony in the third quarter.

He came off second best in a collision with Cam Zurhaar and immediately grabbed at his shoulder.

“It was painful,” Richards told Channel 7.

“Once I got down to the rooms it started settling down a bit and I was like ‘I think I’ll be right here’.

“It was probably soft, bit of carry-on by me in the end.”

The Dogs’ win spoiled North Melbourne’s centenary celebrations but ensured Liberatore’s 250th AFL game was one to remember.

The 2016 premiership hero finished with 27 disposals, two goals, six clearances, 10 tackles and a goal assist.

Remarkably, Bulldogs captain Marcus Bontempelli went through a full game without recording a clearance for the first time in seven years.