West Ham were rumoured to have made a £9million move for the French midfielder, with Arsenal also said to be interested.
But the 21-year-old has cited Mochengladbach qualifying for Europa League football as a major reason behind his move.
“They are a club that focus on young players, there is a good structure, they are playing in the Europa League. I like their project.”
It is this quality of player which the Hammers will perennially miss out on if they do not secure European football.
Manuel Pellegrini spent a great deal last summer and that spree should really have made them the favourites for seventh place, which ended up being occupied by Wolves – who had only just been promoted.
With that being said, the Chilean manager was hit with injuries to key players like Manuel Lanzini, while also having to deal with transfer difficulties such as the Marko Arnautovic saga during the January transfer window.
But next season there are no excuses for Pellegrini and the West Ham players.
If they want to push on and do what David Gold suggested in his tweet and crack the top six, then the first step to that is qualifying for Europe as otherwise being able to bring in the calibre of player to push on will be nigh on impossible.
There is little to suggest that they cannot do that, with the signing of Spanish forward Pablo Fornals for £24m last week a real statement of intent from the club.
For a long time West Ham fans bemoaned the lack of investment in their team.
Now that money is being spent, the next step is to secure European football and attract a top quality of player to the club rather than relying on paying over the odds for them.