Alan Stubbs reckons the team most likely to bring Celtic’s remarkable ‘invincible’ run to an end is not Rangers – but the Hoops themselves.

The Parkhead side stretched their domestic superiority to 56 games without defeat in Wednesday night’s 4-0 win over Dundee to reach the Betfred Cup semi-finals.

Next up is tomorrow’s eagerly-awaited Old Firm encounter with rivals Rangers at Ibrox.

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But Stubbs, the former Celtic defender and Hibs manager, insists Aberdeen are currently the team best suited to testing Brendan Rodgers’ imperious outfit.

And he believes complacency in their own ranks is the greatest threat to Celtic in their quest for a second season unbeaten in Scottish football.

He said: “When you look at it and think about who’s going to beat them, I think the one that can do that is themselves.

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“To go through two seasons unbeaten would be remarkable. Whether they can do it, I don’t know.

“I said ‘no’ to last season and they did it, so I don’t want to look foolish and say that again.

“They just look as if it’s normal service resumed.

“The only team, realistically, that would give them a real game would be Aberdeen.

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“On their day, I think Hearts could make it difficult for them, I think Hibs could make it difficult or them, but whether that reflects in them getting a result, I’m not too sure.”

He added “They’ve steamrollered everyone in Scotland in the last year and there’s no signs of it stopping. 

“The manager simply won’t allow it to happen.”