Corns and calluses are due to too much pressure on an area of the foot. They are common in the general population and can be more common in those who play sports as the pressures on the feet are higher. If the pressure is more diffuse, then that typically causes a callus. If the pressure is more focused on a smaller area, then that typically causes a corn.
The too much pressure might come from the shoes if there is a foot deformity present. That deformity may be a bunion, hallux valgus or a hammer toe. If the pressure is higher under the ball of the foot, then that may be due to a prominent metatarsal head and result in a callus.
The only way to get rid of a corn or callus permanently is to remove the causes. A good podiatrist can easily remove the thickened skin of the corn and callus and this will give pain relief. However, they will come back unless the cause is removed.
There is a popular my that corns have roots that they grow back from if that root is not properly removed. They do not have roots. If a corn is removed properly by a podiatrist it will come back becasue the cause of the corn (the high pressure) is still there, not becasue there was a root that was left there by the podiatrist.
It may be that surgery, for example to fix something like a hammer toe, may be needed to remove the cause. A callus under the foot could be treated with a insole that remove pressure of the areas of higher pressure.
If you have a problem with a corn or callus, then see a podiatrist as to the best options to remove the cause so that it is no longer a problem.