West Ham have made an improved offer worth £30m for Manchester United defender Harry Maguire.
The Hammers had a £20m bid for the England international rejected last month.
West Ham are also expected to pursue a deal for Manchester United midfielder Scott McTominay.
Manchester United are not pushing the players out, but will consider offers that reflect “fair market value”.
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West Ham have an agreement in principle with Ajax over the signing of midfielder Edson Alvarez with the club paying an initial £32m plus £2m in performance related add-ons.
Personal terms have been agreed and Alvarez is expected to fly to the UK on Tuesday for a medical.