Swallow was subbed out in the first quarter of last weekend's loss to Port Adelaide with concussion while Weller is facing at least a couple of weeks out with a hamstring injury.

"David's going OK now," Suns head physio Lindsay Bull said.

"He'll go through the relevant concussion protocols and miss this game, hopefully do everything right and keep tracking well to be available the week after."

The news is the last thing the under-fire Suns need with their season once again threatening to fade out after back-to-back defeats to Fremantle and Port after the bye.

Those losses have left the Suns languishing in 16th going into the trip to Tasmania to face the Kangaroos.

Key defender Sam Collins, who has missed the past two games with an ankle complaint, is again unavailable.

"It's improving slowly, but with Sam missing the last couple of weeks he needs a little block of training before being available for selection again," Bull said.

"We'll keep monitoring him week-to-week."

Australian Associated Press