Sydney Swans coach John Longmire is aware of the threat posed by Port Adelaide ruckman Jackson Trengove, labeling him a "combative beast" and a major threat in Saturday's clash at the SCG.

Trengove has made his name as a key defender in seven seasons with the Power but has been forced to carry the ruck duties for most of the year in the absence of the injured Matthew Lobbe and the suspended Paddy Ryder.

The 25-year-old has been outstanding in his new role despite giving away size and strength to his opponents, and starred in Port's win over the Brisbane Lions last week with 25 possessions (20 contested), 15 clearances and two goals.

Longmire said Trengove represented a massive challenge for his inexperienced big men Sam Naismith and Toby Nankervis, but was confident they had the athleticism to challenge the Power ruckman.

"We certainly hope so, but as a player that's played a lot of key defence he has some unique attributes," Longmire said of Trengove.

"He's used to getting after the ball at ground level, he's used to competing in the air, and all of that was on display last week.

"He's virtually another midfielder, his contested possessions were through the roof and his clearances were incredible for a ruckman.

"He's really hanged the rucking role, particularly for Port Adelaide, but across the competition in regards to what he's doing.

"He's such a combative beast in the ruck and he's fantastic at ground level so it's a big challenge for our boys."

Swans premiership player and valued key position man Sam Reid is running out of time to play senior football this season.

Reid has battled with Achilles and calf injuries, playing just one half of a pre-season game, half a NEAFL match and no senior games.

"We'll have to make a call on him in the next week or ten days as far as his likelihood to get back and play this year," Swans coach John Longmire said on Thursday.

More to come