"I am satisfied, things are going very well," Diawara's agent Franck Belhasen told eurosport.
"He has passed a medical exam and will pass another tomorrow. I am hopeful he will pen a contract by tomorrow night (Tuesday).
"Bolton still have to negotiate a loan deal with St Etienne. It will be a loan deal with an option for permanent move."
Meanwhile, Celtic have agreed a deal to sign Cameroon defender and Bolton target Jean-Joel Perrier-Doumbe.