Celtic have enjoyed an excellent pre-season, which will prepare them nicely for the challenges that lie ahead this campaign. Fitness is always the main goal; results aren’t the be-all and end-all. Nevertheless, victories over Chelsea, Manchester City, and DC United have whet supporters’ appetite for the Scottish Premiership season. Encouragingly, Brendan Rodgers has also taken the opportunity to field several Celtic youngsters across preparatory fixtures, allowing fans to profile who could become future stars at Parkhead. Northern Ireland youth international Francis Turley has taken his chance…