Always build and rebuild your athletes from the ground up. Emphasize training movements that connect and coordinate. Start with fundamental movements and add complexity as the athlete’s gain mastery of the fundamentals. Don’t worry too much about being sport specific; instead emphasize movements that are sport appropriate to prepare the athlete for the sport demands.
Take your time, adaptation takes time it will not happen overnight. If you don’t do this, you are building a fragile athlete much like a house of cards that will blow over in the slightest breeze.