Julian Weigl
The German is the next brightest thing at Borussia Dortmund and is a key player despite his young age. Part of the reason that Dortmund let Ilkay Gundogan go was because they were so confident in Weigl’s ability and he has so far shown that was a pretty clever decision. The only drawback is that if the club don’t start winning things he could want out and Arsenal should be interested.