Charlie Nicholas has labelled Hearts as the "biggest threat" to Celtic's treble hopes as he took aim at Rangers.

After Ange Postecoglou's League Cup victory over Michael Beale's outfit, Nicholas reckons the Hoops now have a huge chance of more silverware this season.

But the former Celtic and Aberdeen man has pinned importance on this weekend's Scottish Cup clash against Hearts at Tynecastle, insisting that Postecoglou's squad will need to be on it from the off.

In the Scottish Daily Express, Nicholas said: "I think tackling Hearts this weekend is the biggest threat to Celtic's treble hopes. Ange Postecoglou's side already have the League Cup in the cabinet and I believe the league is already done and dusted.

"Even if Celtic were to lose at home on Wednesday to Hearts I still can't see Rangers catching them. But the Scottish Cup tie with Hearts is the most intriguing of them all.

"If Celtic can get through then they will see the treble in their sights although as long as Rangers remain in the competition then they will also fancy their chances of going all the way. Ange will be desperate to join the list of Celtic managers who have lifted a treble especially as he just missed out on it last season.

"You feel that Hearts are the type of team who on occasion can pull off a big result against Celtic or Rangers. The next two games are massive in the league and more so in the cup.

"I am not being disrespectful to Rangers here because the Old Firm games look after themselves but the fact they face Hearts in the cup makes it their biggest hurdle to date. I know Celtic beat St Mirren at the weekend but you could see there was still a vulnerability there especially in the first half before Stephen Robinson's side went down to 10 men.

"You saw that with big Ange with his substitutions. St Mirren proved a point that you can get at Celtic. I am expecting something similar against Hearts. I expect Hearts to go full out.

"I think it will be physical and it could be a cold and unwelcoming night which could level things a bit. Robbie Neilson has done a great job at Hearts and quite rightly has received a lot of plaudits.

"They are going to finish third in the league but they will be desperate for silverware. These next two games will definitely be two tremendous tests for Celtic. I wouldn't be surprised if Hearts were to nick a point in midweek and in the cup tie I could see it going to extra-time and Celtic just squeezing through."