Fortune has been clubless since being handed his clearance by Bolton at the start of the season.
The South African has been struggling with injuries in recent years and is hoping to make a comeback in the English Premiership with Keane’s Black Cats.
Although Keane did not want to mention any names, he did reveal that he is looking to bolster his squad during the transfer window.
“We are looking to bring in players,” he told The Journal Live. “We’ve got no Premier League experience and it shows at times. But it’s not right to talk about specific players. That’s the wrong way to go about things,” he said.