Celtic have plenty of returning loanees this summer who will either be keen to impress Brendan Rodgers in pre-season or move on to a new challenge. For now, it is hard to see where the Irishman values existing players on the books at Parkhead as preparations for the new campaign are still a few weeks off. Here on 67 Hail Hail, we do our best to contribute to the wider conversation. Sead Haksabanovic has rarely been mentioned since leaving Celtic last summer on loan to Stoke City amid a storm over an Instagram post where he showed his frustration at a lack of regular minutes at the club. Brenda…