Borussia Dortmund are threatening West Ham plans for Toulouse defender Issa Diop.

The France U21 international is expected in London today for a medical with the Hammers.

However, BILD says French sources suggest BVB are in contact and eager to sign Diop ahead of West Ham.

BVB see the youngster as an alternative to Mainz defender Abdou Diallo.

West Ham are understood to have agreed personal terms with Diop over a five-year contract.