Not to scaremonger, but a calf going 'pop' during sport could certainly be a torn/ruptured achilles.
Someone young and sporty like yourself would do a lot better having it surgically repaired rather than simply leaving it.
Simple test to try:
Kneel on a chair with your foot hanging over the edge (toes to the floor), and squeeze the calf gently. The foot SHOULD start to 'point' in an upward direction. If it doesn't, that reinforces the idea of a ruptured achilles……..
Might be worth a trip to the Doc's…
DrP