Roma midfielder Kevin Strootman has failed in his appeal against a two-match ban.
It means Strootman will miss Roma's vital trip to AC Milan, in which a defeat could seal the Serie A title for Juventus, and the next match against the leaders.
Strootman was retrospectively punished for diving during Roma's derby defeat to Lazio on April 30, and the Italian Football Federation (FIGC) appeal court has upheld the sanction.
A statement published on the official FIGC website confirmed the decision to reject an appeal that Roma had deemed "urgent."
Strootman has played a key role as Roma have challenged for a first Italian championship since 2001.
With four games remaining, they trail Juve by nine points, meaning failure to beat Milan at San Siro on Sunday would keep the title in Turin if the Juve have beaten city rivals Torino on Saturday.