When Brendan Rodgers added seven new faces to his Celtic team this summer, the Hoops boss didn’t just add quality, he also added potential. Spending £11m on Arne Engels and £9.5m on Adam Idah meant that Rodgers not only paid the price for the players he believed could take Celtic to the next level, but the Irishman also secured two players ahead of their best footballing years. Celtic also answered the ever-burning Joe Hart question this summer. When the big Englishman announced his retirement from football, Rodgers knew he had to make a plan to secure one of the most important positions in th…