For GPP i’d go with a simple plan of - 1. Split Squats with Single Arm Tracking - 2. Single Leg Balance to Hip Hinge, with ball at back - 3. Single Leg Squat to Single Leg Stance with Side Pull -
For young player -after you’ve done some mobility and stability work I’d start with something like kneel abdomen brace exercise, split squat abdominal brace exercise and bear crawls and teaching the young athlete about creating and releasing tension / controlling their muscles- you can begin to work on basics like Shuttle Runs, Ball Jumps, Squat Jumps, Pushups, a mixture of lunges and various movements after that in short bursts.
Look, mate — It’s all about movement and short burst exercises with young kids to train their muscles etc. etc — What I suggest was a quick offhand routine ---- It’s a major step up from @Brimmer_Bradley who does laps with 14 year olds and then gets them to spend an hour running into contact with the ball.
Incorrect on all fronts - for a guy that likes to regularly use evidence based argument on here when it comes to sport, you do a lot of diagnosing through a screen.
I think we know the type we are dealing with here kev, savage thick and ignorant, you’d try telling him he is breaking his back dead lifting a weight far too big for him and he’d grunt “fuck off” at you