It is a huge week for Barcelona and it started in the best possible manner as the Catalan club beat Valencia 3-1 in the La Liga fixture on Sunday at Camp Nou.
51-year-old Spaniard Kiko Ramirez has signed for the Bhubaneswar-based franchise for a year with an option to extend after the season.
Emery, who will be leading Villarreal against Manchester United in the Europa League final, had coached Mata during his time at Valencia.
Arsenal trail 2-1 as they host Villarreal in the UEFA Europa League semi-final second leg.
Barcelona beat Valencia 3-2 at Mestalla on Sunday courtesy of a goals fro Lionel Messi and Antoine Griezmann.
Valencia team walk off the pitch after one of their players Mouctar Diakhaby claimed to be insulted racially by an opponent.