THE SYDNEY Swans and North Melbourne will enter round 13 with a few concerns following injuries to Swans ruckman Kurt Tippett and Kangaroos skipper Andrew Swallow at the weekend.

Tippett tore a hamstring tendon in his right knee at a centre bounce ruck contest against GWS, with scans on Monday ruling the 29-year-old out for up to six weeks.

Youngster Harry Marsh will also be unavailable for Sunday's home clash against Melbourne after hurting his hamstring, while forward Sam Reid will miss the next three weeks with a calf strain he picked up in the Swans' NEAFL match on Sunday.

In better news, forward Gary Rohan has been cleared of any damage to his left hamstring after sitting out the last term due to a corked glute that bled into his upper leg.

The 25-year-old will have to get through training this week before being declared a certain starter against the Demons.

Swans defender Callum Mills was assessed for an accidental knock to the throat he received from Giant Jeremy Cameron late in the third quarter, and fellow young gun Isaac Heeney landed awkwardly on his right shoulder in a marking contest in the final term.

North Melbourne faces a nervous wait with five players under an injury cloud ahead of its Friday night blockbuster against Hawthorn.

Swallow's game against Geelong ended prematurely after he was concussed in a tackle from Cat Lincoln McCarthy late in the first quarter.

The captain's head hit the turf and he was assisted off the ground after slowly getting back on his feet.

Midfielder Ben Cunnington hobbled off the ground in the first quarter after receiving a corked left quad just above his knee from Cat Shane Kersten.

Cunnington had ice applied and battled through the match with a pronounced limp, before being rested in the latter stages.

Fellow onballer Nick Dal Santo experienced adductor pain in the first quarter and received medical attention on the interchange area during the second term.

He, like Cunnington, played out the match but was hampered by the injury, while small forward Robbie Nahas suffered a compound fracture of his finger early in the game but also played on.

Defender Shaun Atley's right ankle became caught under a Darcy Lang tackle midway through the fourth quarter and was examined by the medicos on the bench.

On Monday evening, West Coast confirmed ruckman Nic Naitanui will have surgery this week to correct an ongoing Achilles tendon issue and miss up to two months.

The 26-year-old was being carefully managed but the problem flared against the Western Bulldogs at Etihad Stadium in round 11, restricting his output in recent weeks.

Western Bulldogs midfielder Luke Dahlhaus strained the medial ligament in his left knee late in the first quarter against Port Adelaide and took no further part.

The 23-year-old immediately clutched his knee as teammate Tom Campbell crashed into his left leg.

Dahlhaus, who had the knee heavily bandaged, will have scans to determine the severity but is expected to miss a few weeks.

In other injuries at the weekend:

- Forward Daniel Menzel sent a scare through the Cats' camp when he hobbled off the ground with a left ankle injury after slipping on the artificial turf bordering the boundary line in the second term. Menzel played out the game but will be further examined for any ligament damage.

- Suns defender Kade Kolodjashnij was knocked unconscious and stretchered off the ground after receiving an accidental knee to the back of the head from Tiger Sam Lloyd in a third-quarter marking contest. Kolodjashnij was alert in the rooms and was taken to hospital for precautionary scans, which cleared him of any serious damage.

- Bombers captain Brendon Goddard suffered a broken nose in the opening moments against Hawthorn after receiving an elbow from ruckman Matthew Leuenberger in a friendly fire incident. Goddard, who spent several minutes on the bench as Dons doctor Bruce Reid worked to stop the bleeding, managed to play out the game.

- Tigers backman David Astbury was forced down into the rooms early in the fourth quarter with a left ankle complaint, but later returned to the field.

- Blues ruckman Daniel Gorringe had his knee assessed in the third quarter against St Kilda and seemed to be carrying a slight limp.

- Dockers forward Matt Taberner rolled his right ankle after taking a mark in the goal square midway through the third term against the Brisbane Lions. The 22-year-old had his ankle taped and returned to the field.

- Eagles defender Sam Butler strained his groin during the on-field warm-up and was a last-minute withdrawal against Adelaide.