Former FC Barcelona wonderkid Alen Halilovic has now claimed Arsenal have ‘one of the best midfielders in the world’ on their books. The story of Halilovic is one that most football fans of a certain age will remember, with the Croatian midfielder once viewed as the next Luka Modric having become a regular for Dinamo Zagreb at the age of 16 before moving to Barcelona at 18-years-old. Like so many players before him, though, Halilovic couldn’t make the grade at Barcelona, making just one senior appearance for the club before beginning a journeyman career that has taken the playmaker to AC Milan…