My Son Came Home From School With A Hurting Foot.

My son came home from school with a hurting foot. He kicked a buddy in the shin this morning.... boys... and says the bottom of his foot suddenly hurt. He sat down took off his shoe but did not go to the nurse. After walking on it all day it is swollen and a bit bruised in the arch area. Very tender to the touch. He says he heard a pop when he kicked his friend. It being a Friday afternoon I am trying to determine if he needs to be seen or not. Thanks for the help!