Celtic play Dundee United in the Scottish League Cup final on this season . Ronny Deila 's side are bidding to win the domestic treble Sunday . Deila says losing cup final in Norway was the worst thing he has done .
Celtic play Dundee United in the Scottish League Cup final on Sunday . Ronny Deila 's side are bidding to win the domestic treble this season . Deila says losing cup final in Norway was the worst thing he has done .