The Senegalese striker was at the Academy of Light on Monday to finalise his temporary shift to Wearside which could be made permanent by the Black Cats at the end of the season.
"He's in the building at the moment.
"We hope to pull off a deal until the end of the season with a view to a more permanent move.
"He's experienced the Premier League before with Hull City last season and scored five goals in 12 matches. I hope he can emulate that for us or maybe do even better."