Juventus are confident Arturo Vidal will not be lured away by Manchester United in the summer transfer window.
Harrison Reed has committed his future to Southampton after signing a new four-year contract at St Mary’s.
The 34-year-old has agreed terms with Blues and passed a medical but the club are waiting on a visa application before a one-month deal is completed.
Former Senegal international Diop, who helped West Ham to promotion to the Barclays Premier League last season, has impressed on trial at St Andrew's.
He has also played in England for Fulham and Portsmouth, with whom he won the FA Cup in 2008.