Blackman is set for his fifth loan move, after spells at Middlesborough, Ostersunds, Wycombe Wanderers and Sheffield.
The 24-year-old is a product of Chelsea's youth set-up, but he has not yet broken into the first team.
As reported by 'Sky Sports', the goalkeeper is undergoing a medical on Saturday, ahead of a season-long loan deal to Leeds.
If the move goes through, Blackman will be the second deal for a Chelsea player by the Championship side this summer, after Lewis Baker also joined on a season-long loan..