"It's football. That's the way it's always been. It's a physical game. You never know who's going to be up and who's going to be down," Zbikowski said Tuesday. "If you're on a team, you've got to be practicing like you're going to be starting, because most likely — if you really look at the NFL — 53 people on a team, there are going to be injuries, and eventually you're going to be playing somewhere."