Are your heels touching the ground when you are playing?
If not your calf is always activated which is causing the issue.
Are you warming up/cooling down enough?
Introducing the Bone Saw: Calf Smash Redux
Episode 303: It’s Not Rocket Science, It is the NASA Calf Game
Episode 237: Heel Cord Love
Episode 194: Why Do You Hate Your Calfs?
Episode 84: Calf Blaster Does Sound Cooler Than Dorsiflexion Blaster
Episode 25: Heel Cords of a Cheetah, Achilles Well Being