Aston Villa sold one player in the summer who hasn’t seen his move work out as well as he would have liked. Aston Villa’s hand was forced by PSR during the summer transfer window, prompting Unai Emery to offload multiple first-team stars. One notable sale was record-signing Moussa Diaby. The Frenchman’s departure to Al-Ittihad just one year after joining came as a shock but the 25-year-old sought Saudi Arabian riches over playing in the Champions League. Emery also sanctioned the £20 million exit of academy star Omari Kellyman to Chelsea. Initially signed for £600,000 from Derby County in July…