Joe Hart was the subject of conversation yesterday as Celtic asked the fans to fire questions at their retiring hero. We have already discussed Joe Hart’s love for Celtic, the moment the Parkhead support really blew him away and now the retiring legendary goalkeeper has picked out the Celtic teammate he believes is so ‘important’ for Celtic. Over the past three seasons, Hart has played with the likes of the solid Cameron Carter-Vickers and the goalscoring exploits of Kyogo Furuhashi. But it’s Callum McGregor who is the focus of his attention as Hart pays tribute to the legendary Celtic captain…