The Burkina Faso international scored 11 goals and got nine assists in 88 matches at the Vitality Stadium
Brentford have agreed a club record deal worth up to £42.5m for Bournemouth forward Dango Ouattara.
The 23-year-old is set to travel to London on Friday to undergo a medical.
Sources close to Ouattara told BBC Sport he wanted to leave, having not had a prominent role at Vitality Stadium.
The Burkina Faso international scored nine goals in 37 appearances in all competitions for the Cherries last season.
