The Sydney Swans have suffered an injury blow with Gary Rohan suffering a susepcted hamstring strain in the second quarter of Thursday night's clash against Port Adelaide.

Rohan went straight to the interchange bench after suffering the injury, where club officials confirmed the 24-year-old would take no further part in the match.

He was immediately substituted out with Harry Cunningham activated.

Rohan, who has played every game so far in 2015, was responsible for the highlight of the first half with a leaping mark in the first quarter.

The loss of Rohan will put added pressure on the Swans' forward line, given the club came into the match without suspended pair Lance Franklin and Kurt Tippett.

The former first-round draft pick has battled injury throughout his career, notably suffering a horrific broken leg in 2013 which saw him miss almost a year-and-a-half of football. 

And worse was to come in the third quarter when Richards was slung to the ground in a tackle by Jay Schulz and made hard contact with the SCG turf.

The veteran Swans defender lay motionless on the ground in the moments after the tackle, with Schulz immediately calling for the medical staff. Play was stopped for about five minutes as the Swans medical staff assessed the injury before Richards was placed on a stretcher and taken off the ground on a motorised cart.

In an encouraging sign for the Swans, Richards appeared conscious as he was taken to the dressing rooms.