NORTH Melbourne has declared Daniel Wells fit to play Collingwood after the star midfielder underwent a dramatic pre-match fitness test on Friday night.

Wells sent a major scare through the Roos' camp when he walked off Etihad Stadium as his teammates went through their warm-up, with club medicos rushing down to the rooms after him.

The 31-year-old reappeared shortly after and underwent a brief fitness test around the boundary line, running through 30m at about 75 per cent pace several times before disappearing back down to the changerooms.

North emergencies Corey Wagner and Ed Vickers-Willis both started warming up as Wells consulted medical staff, but just eight minutes before the bounce the Kangaroos confirmed Wells would play.

Friday night's game will only be Wells' second match back after he missed two games sidelined by a calf/Achilles complaint.

The Roos are already missing a host of key players and could ill-afford another injury, with gun forward Jarrad Waite missing the Pies clash – sidelined for his fourth game in five weeks - succumbing to an ongoing hip complaint

Waite told Triple M pre-game he was "hopeful" of returning against St Kilda next round.