Valencia have made a bid to sign Manchester United midfielder Tom Cleverley, according to Sky sources.
Bayern Munich are close to signing Xabi Alonso from Real Madrid after the two clubs agreed a fee for the midfielder.
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.