Defender Shane Stefanutto has been forced to leave training in another injury scare for Brisbane Roar ahead of their clash against Melbourne Heart this weekend.

With star striker Besart Berisha (hamstring) and Irish import Liam Miller (calf) already sidelined, the sight of Stefanutto painfully limping off at training on Wednesday with a suspected hamstring complaint was the last thing the Roar wanted to see.

Making matters worse, George Lambadaridis (knee) is out for the season while Kofi Danning (knee) is not expected to return until December.

Coach Mike Mulvey said he was not concerned about the attrition rate despite the Roar's bold decision to sign the minimum 20 players for the season rather than the permitted 23.

"Our conditioning sessions are pretty tribal. We push the players to the edge," he said. "I am not sure what happened to him (Shane) at the moment but he is in there seeing the physio.

"Injuries are part and parcel of football and test the depth of your team. We are in a situation where we have to call on people who have not been playing on a regular basis.

"But I have confidence in the players that we have got," Mulvey said.

Roar host winless Heart at Suncorp Stadium on Sunday afternoon.

Youngsters Ben Litfin, Kwame Yeboah, Devante Clut and Brandon Borrello are contenders to win a call-up as cover for the injuries.