Aston Villa and Manchester United are locked in a transfer battle to sign a Europa League-winning midfielder as Unai Emery eyes a replacement for Douglas Luiz. Aston Villa kick off their Premier League campaign away at West Ham on Saturday evening but supporters still have concerns over their transfer business. Whilst Unai Emery has captured eight new signings, Villa have still arguably not replaced Douglas Luiz, who completed his move to Juventus. Enzo Barrenchea, Amadou Onana and Ross Barkley have all arrived as central midfield options attempting to fill the Brazilian’s void but Emery still…