EX-MAGPIE Marley Williams' first season at North Melbourne is over because of a persistent back injury.

The Kangaroos' general manager of football, Cameron Joyce, confirmed the 24-year-old defender, who played in the club's first 13 matches this year, would likely require back surgery.

Williams will firstly have a shoulder operation after previously undergoing an arthroscopic labral repair on his left shoulder.

He was a late withdrawal because of his back for North's round 15 clash with the Gold Coast, and the club was unable to get the problem under control. 

"Over the past six weeks, we’ve tried numerous non-surgical treatments for Marley, but without the desired results," Joyce told nmfc.com.au. 

"The last resort was and always has been surgery, but unfortunately we’ve run out of time to get Marley back before the end of the year and will now focus on getting him right for the 2018 pre-season.

"This will mean a likely procedure on his back, but first we’ve opted to get his shoulder repaired, which he’s been carrying since round seven. On medical advice, these operations can’t be conducted simultaneously." 

Sam Wright will finish the year without playing a senior AFL game, with North Melbourne preparing to send him in for ankle surgery. The 116-game defender managed only three VFL games around foot and ankle issues.

The Roos have also ruled out long-term knee victim Paul Ahern, Jamie Macmillan (finger), Ben Jacobs (lower leg), Ed Vickers-Willis (PCL), Declan Watson (ACL) and Mitch Hibberd (shoulder) for the season. 

Key forward/wingman Jarrad Waite (calf) will miss the next fortnight, putting him on the sidelines for the fourth time this year and third through injury.