The former Parkhead goalkeeper now watches on as a fan and was delighted to see his old club get their mojo back with a win over Besiktas - a first victory in this year's Europa League.

Hart has been taking a closer look at the domestic form and insists Celtic are not doing any worse than in previous title-winning campaigns.

And he has picked out Duran and Osmand as two matchwinners in the side.

"That’s the thing about that club, and that is why I adore it, and I’m so pleased that I got to spend time there and be a part of it. The expectancy and the expectation, unless you are a Celtic man or a Celtic person, you wouldn’t understand, because, like you say, they’re still top," the Englishman told the Overlap Daily.

"I think Rangers have a game in hand because they played in a cup semi-final at the weekend, but even if they win that, they’re still a point behind. And domestically, Celtic have lost two and drawn one in 11 games. It’s not the reason. I was looking at how they’ve started leagues in the past eight, nine years, and they’re right up there with what they do, but they’re not flowing. The strikers aren’t scoring.

"Camilo Durán has been an absolute saviour this season. Him and Callum Osmand came on, I think, around the 60th minute, with it looking ominous, 1-0 down against Besiktas, who were flying high, a good team.

"And Callum Osmand’s first touch, he smashed it through bodies. He’s got that magic moment in him. He had it last year. He’s the one who scored when they beat Heart of Midlothian 3-1, and he got to run the length of the field on his own. He scored a couple of big goals in the title run-in as well.

"But it made me happy to feel the stadium shake through the TV, because that stadium does go wild, and people are talking with their feet. It wasn’t a sold-out crowd, which is so unlike Celtic.”