The Brazil international has been stung by Serie A authorities following his red card during an Italian top-flight fixture on Sunday.
Juve were seconds from securing a 2-1 victory when their South American forward was sent from the field.
Having been drawn into a tussle with Di Francesco, Costa proceeded to aim his head, elbow and saliva at his opponent.
Costa has now been made aware of his punishment, with the referee’s match report and video evidence having been reviewed.
He has been charged with violent conduct and ruled out of four Serie A fixtures.
He said: “It is only right that he is fined and he certainly will be.
“I was surprised by his reaction. We have suffered a goal, a red card and a suspension, which will be long.”
Reports in the aftermath of the incident suggested that Costa had reacted angrily to a racist barb aimed in his direction by Di Francesco.
The 24-year-old Sassuolo winger has strongly refuted those allegations, saying: "I am deeply disturbed by speculation and inventions that have appeared in some national media.
"It is all offensive and disparaging.
"I do not allow myself to be attributed to racist behaviours and phrases that do not belong to my ethical values and which are the fruit of others' imaginations.
"I ask for and I demand respect."
Juventus, who saw Cristiano Ronaldo open his goal account for the club by bagging a match-winning brace against Sassuolo, currently sit top of the Serie A standings.