Diafra Sakho has refused to travel with West Ham for their pre-season tour of Austria, according to Sky Sports.
The Senegal international striker has made no secret of his desire to leave West Ham this season and it is thought that he wants to reunite with his former Hammers boss Sam Allardyce at Sunderland.
Sakho has scored 15 goals in 44 Premier League games for West Ham since joining two years ago for £4.5m and bizarrely could now move for close to £15m.
He missed a large chunk of last season though injury but then returned to largely play on the flanks.
His agent Mark McKay told Sky Sports News last month:
“West Ham are looking for that top, top striker and Diafra is a bit concerned, that once they find that striker, what his place in the team is going to be.
“If he gets those assurances from West Ham, I am sure he’ll be happy to stay there, but otherwise he may be looking elsewhere.”