Celtic crashed to a 2-1 defeat against Kilmarnock over the weekend.
Goals from Chris Burke and Stuart Findlay ensured a win for the home side.
Celtic did well to get their noses in front but the hosts scored twice in the second half to secure the three points. Leigh Griffiths had put the visitors ahead in the first half.
The Scottish champions failed to impress with their performance and Kris Boyd has now singled out Scott Sinclair’s display on Sunday.
The Kilmarnock player believes that Sinclair went into hiding when his side needed him to step up and deliver.