NORTH Melbourne captain Brent Harvey will have surgery on his elbow in the next 24 hours as the club prepares for his lengthy stint on the sidelines.

Harvey, who dislocated the joint early in Saturday night's loss to Richmond, had played 101 games in succession and missed just nine in the last 10 seasons.

Chief of football Donald McDonald said Harvey had the professionalism to make ground during a prospective 12-week recovery but re-iterated the gravity of his situation.

"It's major surgery. They've got to re-attach both the tendons in his elbow," he told kangaroos.com.au on Tuesday night.

"It's not a great result for Boomer and we'll know more once the doc performs surgery.

"We've got a great medical team and I'm sure (doctor) Con (Mitropoulos) and the boys will keep a good handle on it all."

McDonald also confirmed that emerging centre half-back Lachie Hansen, one of the Roos' better performers in the first four rounds of the season, would need to fight back from a torn hamstring that could ground him for up to six weeks.

Hansen, 20, left the field in the fourth quarter of Saturday night's game and it was initially thought he was suffering severe cramp.

"When he came off the ground he still had a spasm in the muscle," McDonald said. "After a while Con said, 'We can't put him back on because it doesn't feel like a cramp. It feels like something that could be a bit more serious'.

"It's a blow for Lachie but it's a big blow for us. He was really looking good.

"The positive thing is at least we know that he can hold down centre half-back for us or eventually even centre half-forward for a long time to come."

Midfielder Daniel Wells (hip) and forward Matt Campbell (hamstring) will miss Friday night's clash with Collingwood but should return against Port Adelaide in round seven.

Campbell sat out parts of Tuesday's training session and McDonald said North would not be persuaded to take any risks with him or Wells.

But key forward Robbie Tarrant (knee soreness), Liam Anthony (foot stress fracture) and Jesse Smith (hamstring) have all started running and could push for VFL selection within the coming weeks.

"Now that they can run, it's a matter of how quickly they can get to a level where they can play," McDonald said. "They (Tarrant and Anthony) both had really good pre-seasons.

"It's really positive news.

"If we get a bit of luck with some of these injuries, in the next month or so we'll start to get some of these guys available for senior selection, which will be great."

Second-round draftee Sam Wright, who strained a medial ligament in the pre-season, suffered a knock to the same knee in VFL side Werribee's loss to Williamstown on Sunday.

"We went for the more cautious approach and took him off the ground," McDonald said. "Sammy's jumping out of his skin to play this week so he should be alright."