NORTH Melbourne captain Brent Harvey could miss up to three months of football after dislocating his elbow against Richmond on Saturday night at Docklands.

Harvey, 30, left the field at the 12-minute mark of the Kangaroos' 36-point loss to the Tigers on Anzac Day night after being tackled by Matt White.

He was helped from the field as he clutched his left arm and spent the remainder of the game on the bench after having his elbow reset in the rooms.

Coach Dean Laidley said Harvey will have scans on Sunday to determine the damage surrounding the dislocation, with the best-case scenario a month and a half out of the game.

"He's in for a long stint on the sidelines, Boomer," Laidley said, after the match.

"He dislocated his elbow, and if he's torn the ligaments it will be at least 12 weeks, and if they're intact, six to seven."

West Coast's Beau Waters suffered the same injury in round 13 last year, with complications ruling the Eagle out of playing at all this season.

Western Bulldog Shaun Higgins also had the troublesome complaint in round 13, 2006, and missed the rest of that year.

Although the tempo of the game shifted after Harvey left the field, Laidley said he didn't believe his absence affected his teammates.

"He didn't touch the ball so I wouldn't have thought he had an influence on the contest," he said.

"Do you think when they're running to kick the football, they think 'Gee, our captain is not out on the ground?'

"I don't subscribe to those theories."

Laidley confirmed young defender Lachie Hansen strained a hamstring in the fourth quarter and will miss two to three weeks, but said Michael Firrito was fine after playing out the game following a first-term ankle injury.

He said it was disappointing to see Hansen, who was the No.3 draft pick overall in 2006, sustain an injury after hitting some form.

"He's been probably one of our biggest improvers. We've played him down back and tonight when Richo pushed up to the wing, we thought he's got the tank to be able to do that, and I thought he was doing really well," Laidley said.

"Unfortunately, then this happens."