This will no doubt be a kick in the teeth for the London club who will have been delighted to have held off their Premier League rivals in the reported pursuit of their own French stopper Diop earlier in the window.
Keeping hold of Diop would have been a massive positive for everyone involved at the London Stadium, but their reluctance to let go of the 22-year-old seems to have affected them in a negative manner as well as a positive one.
Kakak will now have a decision to make after reportedly holding talks with many different clubs, with the realisation that both Bayern Munich and Manchester United being able to offer European football – a move to London seems highly unlikely for the youngster.
Manuel Pellegrini will now most likely have to look elsewhere in his bid to strengthen his back line, something that will no doubt hurt the Hammers’ plans as well as their pride.
The Stuttgart defender would have been the perfect option for West Ham, with Turkish outlet Hurriyet reporting the youngster only holds a release clause of £13.3million.
Kabak offers great defensive attributes, averaging 3.7 clearances last season per game, alongside 2.5 tackles [WhoScored] while at only 19-years-old he holds Champions League experience for his former side Galatasaray.
There are always two sides to every story, with the positive of keeping Diop at the club more than likely meaning one of their transfer targets will move elsewhere, with Manchester United moving their attention slightly.