Sunderland target Diafra Sakho has submitted a transfer request at West Ham in a bid to hasten his summer departure.
Speculation last night indicated that Sakho had asked to leave the Hammers and those reports are understood to be accurate, with the Senegal international growing frustrated with his situation at the club.
Sakho has remained Sam Allardyce's main summer target to boost his attacking ranks, despite Sunderland seeing a formal bid rejected by West Ham last month.
West Ham have been prepared to sell Sakho, but they have put any move on ice until a replacement frontman arrives - a search which has proved frustrating after Carlos Tevez became the latest potential deal to fall through.
However, the 26-year-old - absent from West Ham's pre-season trip to America because of illness - is not prepared to wait that long and wants his future resolved.
The Echo understands that by submitting a transfer request, Sakho hopes to force West Ham's hand and hasten his departure.
Allardyce was responsible for bringing Sakho to the Premier League two years ago when the then West Ham manager signed him from Metz in a £3.5million deal.
And the prospect of linking up with Allardyce again is thought to appeal to Sakho, as does the possibility of regular first-team football.
Allardyce has been desperate to bring in a quality frontman this summer to either use alongside or instead of last season's top scorer Jermain Defoe.
Sunderland will have to shell out around £15m to land Sakho - which would break their club record transfer fee.
However, Sunderland are thought to be prepared to spend big on a striker, particularly as the new television deal has significantly increased price tags so far this summer.