Twin Cities orthopaedic surgeon Dr. Michael Freehill has five key points to consider before and during training with weighted baseballs:

1. Is the player skeletally mature? Is he done growing?

2. Proper screening and assessment of core strength, rotator cuff health and appropriate motion in the shoulder and elbow.

3. A progressive program of 12 to 14 weeks of prep work, ramping up before introducing weighted balls.

4. Balance weighted ball training with core strength training.

5. Must have proper throwing mechanics.