Blake will sign on the dotted line once the terms of his departure from Birmingham City have been decided upon.
If agreement is reached early enough, he could join his new team-mates on the pre-season tour of Norway.
The Middlesbrough-born forward has scored over 120 goals in a 300-game career that has taken in spells with Darlington, Nottm Forest, Bradford and Burnley.
"He will offer us something different in attack and I am really delighted," Kevin Blackwell said at the weekend.
"The chairman Ken Bates has been absolutely brilliant. It shows how far the club has come."