Sam Naismith’s continuity has taken a hit after the ruckman was a forced omission from the Sydney Swans’ Round 9 line-up.

Naismith tweaked his medial ligament in last weekend’s win against North Melbourne, the same injury which subsequently outed him for the Sydney Derby and the following two weeks.

He returned for the win over Brisbane, only to play hindered for most of the game against the Roos after aggrevating the same knee during the early stages of the clash at Docklands.

The 24-year-old was given every chance to prove his fitness this week, but the 18-gamer was restricted to light duties during Thursday’s final training session which effectively struck a line through his name.

It was too early for coach John Longmire to put a definite timeframe on the ruckman’s recovery.

A full update on Naismith’s condition will be provided early next week in the HCF Injury Update with Head of Football Tom Harley.

After enduring an interrupted pre-season due to shoulder surgery over the summer, he blitzed his rehabilitation to play in the opening three games of the season.

It was in the closing stages of training, two days out from the Round 4 clash with GWS, where Naismith strained his problematic medial ligament.

He’s averaged 10 disposals and 25 hit-outs in his five games this season.

Pending other factors, he’ll need to stave off Callum Sinclair or Kurt Tippett for a ruck spot in the Sydney Swans’ senior outfit when available while Darcy Cameron is continuing to press his case for a debut at NEAFL level.

Naismith was replaced by Tippett in this week’s side to tackle St Kilda on Saturday afternoon.