Dubois will get shot on the massive time as Usyk battle confirmed for August
The battle will happen on the 24,000-capacity Tarczynski Arena in Wroclaw.
WBA necessary challenger Dubois final fought in December, recovering from a leg damage to defeat Kevin Lerena by means of knockout.
Pound for pound star Usyk is the IBF, IBO, WBO and WBA champion having defended his titles in opposition to Anthony Joshua final yr.
The 36-year-old had been anticipated to battle Tyson Fury to find out the primary undisputed world heavyweight champion since Lennox Lewis in 2000.
Talks, nevertheless, fell by and experiences now counsel Fury will as a substitute meet former UFC star Francis Ngannou in an exhibition bout.
While boxing has loved a yr full of massive fights in different divisions, the heavyweight scene has hit a gridlock.
Still, Joshua is widely expected to face Deontay Wilder in Saudi Arabia this winter amid experiences suggesting a rematch with outdated rival Dillian Whyte is edging nearer.