Celtic are sixth in the Scottish Premiership table after a shock defeat to Kilmarnock today.
Brendan Rodgers’ side have only managed to pick up 10 points in their opening six games, which has come as a surprise to everyone.
The Bhoys had led at Kilmarnock. Leigh Griffiths put the visitors ahead just after the half hour mark.
But Killie hit back in the second half. Chris Burke’s long range strike drew the scores level and deep into stoppage time, Stuart Findlay headed in against his former club to clinch a dramatic late win.
With Celtic struggling at the start of their league campaign, they should now be taking their title rivals very seriously.
Celtic are gunning for their eight consecutive league title, but could Hearts and Rangers threaten that?
Here is why Celtic must take these two teams very seriously, or risk losing out on the title for the first time since 2011.
MORE CELTIC STORIES
Hearts
Hearts are absolutely flying this season. Craig Levein has got his team playing good football and picking up results.
After six games, they are unbeaten. Hearts won their first five matches, but were frustratingly held by Livingston this weekend.
Nonetheless, the Jambos already have a five-point lead over second place and a six-point gap above Celtic.
Could Hearts win their first league title since 1960? They are certainly showing signs of promise.
Rangers
Celtic fans will not want to admit that Rangers are close to closing the gap between the two sides.
For several years now, Celtic have dominated the bragging rights in Glasgow.
But under Steven Gerrard, there is renewed hope and Rangers have spent money to improve their squad.
The Gers are above Celtic in the table and whether they like it or not, the Bhoys are going to have to pick things up or risk falling behind Rangers this season.