Core is great, but without a solid foundation all quick hip movement and application of power through the foot is not possible. Everybody likes upper body days but without the legs to support the work needed to be put in up top the metaphorical skyscraper falls over.
Workout:
Dynamic Warmup 30/30
Jump Cycle 4 x
Pyramid Squat 15-10-5-10-15
ALOHL 50 x HT
Rest as needed