Sergi Roberto has signed a new contract at Barcelona, committing to the club he first joined at 14 until the summer of 2022. A €500m buy-out clause has led to some raised eyebrows, but the versatile 25-year-old is a precious component in Barcelona's squad.Expert testimony "Sergi Roberto is a player to look out for over the next few years. When he bursts onto the scene, he'll catch a lot of people by surprise”Josep Guardiola, former Barcelona coach, on the 19-year-old Sergi Roberto