Are NFL football players changing jerseys every game?

It depends. Some teams will change jerseys periodically, some teams will wear one home and one road, and an alternate, if applicable, throughout the course of a season. Some players will wear a jersey for one game, if it is a throwback, like the Cowboys on Thanksgiving. Sometimes a jersey is worn for one game and then sold for charity. When Emmitt Smith broke Walter Payton's rushing record, he wore 4 different jerseys, one for each quarter. Smith kept the jersey worn to break the record, and the other three were given to various people in the Cowboys organization.