The Eintracht Frankfurt star has become West Ham's top striker target since missing out on Maxi Gomez last week, and a deal appears to be close.
Sky Sports claim Haller, 25, is on his way to London to undergo a medical, with a £45million deal agreed with the Bundesliga side.
The Guardian have since reported that there are fears West Ham may be hijacked, as there is late interest from elsewhere, but it's believed that Haller has told the Hammers he's impressed with their project and ambition under Manuel Pellegrini.
Haller, who hit 15 goals and nine assists last season, represents a major coup for West Ham if they can get a deal over the line having starred in Germany.
What's interesting is that, amid fears that West Ham may yet miss out, Haller's teammate Marco Russ has had his say on the striker's future.
Frankfurt may feel that, whilst Luka Jovic's exit was justified because Real Madrid came calling, Haller isn't really making a huge move by heading to West Ham.
The money on offer in the Premier League will be appealing, and the player himself may yet feel that playing in England may enhance his chances of picking up a first French international call-up.
Have something to tell us about this article?