Star midfielder Andrew Swan may have played his last game for the Maitland Magpies with scans revealing a torn ACL and meniscus damage to his knee.
The injury usually requires at least 12 months recovery and may prompt Swan to retire.
The Magpies will also be without Matt Comerford for the Northern NSW NPL finals and perhaps part of 2021 with a knee injury.
Sidelined for almost two years with injury, Comerford had returned at the start of this season but faces an extended period in recovery from a medial collateral ligament injury.
The Magpies had been hoping for good news on Swan's knee but scans revealed the worst.
The one positive is that they are confident Andrew's brother Matt Swan will be fit for week one of the semi-finals.
The Magpies booked their spot by defeating Valentine 1-0 last Sunday.
Maitland have the bye this week and will not know who they will face in week one of the finals until after the round of games.
Depending on results they could finish as high as third and receive a double chance, fourth and host an elimination final or fifth.
Newcastle Olympic and Charlestown Azzurri are most likely to grab the final two spots, however, Lambton Jaffas are still in the running.
"The week off will certainly help the boys with those niggles at the end of a season and hopefully give both Swan boys the chance to recover," Rutherford said.
"We do have coverage, however, with Sean Pratt, Joey O'Connor, Sam Webb and Alex Bozinovski all capable of playing midfield and in good form."
Maitland secured their spot in the finals with Braedyn Crowley scoring his 13th goal from 13 games this season.
Maitland scored soon after the half-time break with James Thompson stretching to intercept a pass coming out of defence and directing the ball in the same action to star Crowley who was lurking just outside the penalty area.
Crowley controlled the ball in the centre of the field and then struck the ball into the bottom left corner just wide of a diving effort by the keeper.
Meanwhile, Weston Bears finished the 2020 season with a 3-0 win against Lake Macquarie on Saturday.