West Ham United had better prepare for a huge battle ahead with Arsenal set to go all out to sign 22-year-old star in the summer transfer window. The upcoming summer transfer window will be a vitally important one for both West Ham United and Arsenal. Hammers boss David Moyes desperately needs to bolster pretty much every area of his squad before the start of next season. One specific area that seems to go under the radar though, is the central midfield department, with a dynamic, energetic and physically powerful ball carrier required at the London Stadium. With that in mind, Amadou Onana of …