NORTH Melbourne's second selection in last year's NAB AFL Draft, Daniel Nielson, will miss the entire 2015 season after rupturing an anterior cruciate ligament.

North announced the key defender's injury on its official Twitter account on Thursday afternoon.

"Unfortunate news today, Daniel Nielson has ruptured his ACL and will require a full reconstruction, ending his 2015," North tweeted.

The 18-year-old injured his left knee in a tackling drill.

"It's extremely unfortunate for Daniel and we will be supporting him throughout his rehabilitation and ensuring he comes back bigger and stronger for the 2016 season," football director Geoff Walsh told the club website.

Nielson will see a specialist on Friday and a plan for his surgery and rehabilitation will be put in place.

North recruited Nielson from Eastern Ranges at pick No. 25 in last year's draft.

He impressed North's coaching staff over his first pre-season with his hard-nosed competitive streak, earning a game in the round one NAB Challenge game against Adelaide.