Big guys like Noah and KO may have flat feet (I am not certain of this, just my estimation).
People with flat feet will have less of an arch in their feet and thus the fascia will be in a default state of stretching. With each step the tiny fibers will experience "micro tearing".
Wearing sneakers (to play basketball etc.) which have too much rubber at the heel side causes more forceful impact to be absorbed at a concentrated area.
Another factor is muscle contraction and prolonged tightness. With each step during running or each jump for a rebound or shot, the calves will contract and if they do not get a chance to relax this causes a baseline state of constant muscle tightness. The prolonged tightness irritates the Achilles tendon causes it to tighten and pull on the heel.
So imagine, each time you take a step and you are on your tippy toes there is a pulling direction one way and each time your calves contract (Achilles tighten up) there is a pulling direction going in the opposite direction.
This is where the fascia becomes aggravated. Without prolonged rest there is no way for the muscles to relax, no way for the Achilles to rest and no way for the fascia micro tears to heal back up.
Things you can do without going to see a health care pro:
1.) Rest
2.) Do not wear sneakers, in fact do not wear anything, go bear foot as much as you can.
3.) Build up the arch in the feet, use a golf ball, tennis ball, ping pong ball, even a beer bottle and roll those things under your arch.
4.) Heating pad and massage to relax the calves and reduce the burden on the Achilles tendon
5.) Nutrition and re-hydration, when we sweat and urinate we lose water/fluids, and we also lose minerals, vitamins etc. We got to replace those nutrients lost and I am sorry gatorade and other sports drinks are really bad for you and don't cut it. Drink 16oz of filtered spring water with a half tea spoon of sea salt to get some trace minerals. Coconut water is a good one too. Eat fruits and veggies. Eat meat to get complete proteins for repair.
Without proper nutrition, without re-mineralizing and re-balancing the electrolytes the body will have a tendency to stay on the contract side instead of the relaxed side.