EMERGING North Melbourne forward Mason Wood has suffered another injury setback, with a knee injury set to sideline him for three weeks.

Wood had been returning from a hamstring strain he suffered at training in late February, a week after kicking two goals in North's opening JLT Community Series game against the Sydney Swans.

The 23-year-old had been cleared to resume in a VFL practice match with Werribee last Sunday, but experienced pain in his knee after training last week and underwent surgery on Tuesday.

“Scans revealed a tiny bone fragment floating in his knee joint that was unrelated to the previous hamstring injury. As a result, Mason underwent a minor arthroscope on Tuesday to wash it out," Kangaroos football manager Cameron Joyce said.

North also said defender Sam Wright would need "some more time" to recover from an ankle injury.

Wright had surgery on both ankles after his 2016 season ended prematurely, but returned for North's final JLT game against GWS and played a VFL practice match the following week.

However, the 26-year-old has been sidelined since.

Midfielder Declan Mountford will have to pass a fitness test this week after copping a knock to his AC joint with Werribee on Sunday.

Wood said his latest setback stemmed back to an injury he suffered in his first season with the Roos in 2013, but involved a non-weight bearing area of the knee that was not expected to trouble him now the floating bone had been removed.

"It's been a long time since I played AFL footy, so any sort of setback is a bit disappointing. But as far as setbacks go this won't be much and I'll back out there as soon as possible," Wood said. 

Wood said his hamstring was back to full strength, and he was optimistic he would return on schedule, if not sooner. 

"(I'll be back in) two to three weeks hopefully. (I'm) just basically waiting for the scars to heal, so once they do I'll be right to go," Wood said.

"I'll be itching to get back there because it's been such a long time."

Wood is one of North's brightest young prospects.

The 192cm forward enjoyed a breakthrough start to his fourth season at Arden St last year, impressing with his elite endurance and contested marking as he kicked 12 goals in eight games.

However, he suffered a medial ligament injury in round 16 against West Coast and, despite striving to return for North's finals campaign, did not play another game in 2016.

Wood has played 16 games for the Roos since being taken at pick No.41 in the 2012 NAB AFL Draft.

Provided he can get his body right, the former Geelong Falcon is likely to enjoy extended senior opportunities in 2017.