Celtic manager Ronny Deila refused to blame the match officials for his side's defeat to Dundee United and instead demanded his side sharpen up both in defence and in front of goal.
Dundee United ended Celtic's eight-match winning run with a 2-1 victory over the Scottish Premiership leaders at Tannadice.
Celtic boss Ronny Deila has praised Dundee United for maintaining their standards despite selling their star players.
Ronny Deila says he has plenty of sympathy for Aleksandar Tonev after the banned winger resumed a seven-game domestic suspension ahead of Celtic's trip to Dundee United on Sunday.
Dundee United will be without the suspended Paul Paton for the visit of Celtic on Sunday after the midfielder's appeal against a spitting charge was rejected.
Celtic winger Aleksandar Tonev says he is not a racist despite losing an appeal against his seven-match ban for abusing Aberdeen full-back Shay Logan.
Celtic manager Ronny Deila hopes any UEFA punishment does not impact on their eagerly-awaited clash with Inter Milan after the club were hit with the latest of a series of disciplinary charges by the European governing body.
UEFA has opened disciplinary proceedings against Celtic following a crowd disturbance at their Europa League Group D match away to Dinamo Zagreb last Thursday.