Brendan Rodgers has spoken consistently about the need to add quality to his Celtic team for many months now. The Celtic boss first breached the subject after the Champions League group stage exit last season and with no new signings added to the squad yet this summer, the Parkhead support will be hoping that Rodgers is being very thorough with his selections. Because what they cannot afford to do is continue to sign project players and hope that they will turn on performances on Europe’s big stage. Celtic need experienced players who have been over the course and players who know what it take…