Highly doubtful it's his tibia. Fibulas (not fibias) are broken all the time in football. It's a small bone that is easily broken, especially just above the ankle, and it's often mistaken for an ankle sprain until they do the x-rays.
The tibia is the larger bone in the lower leg, and if that breaks, then you have a slightly bigger problem.
Break, fracture, no big difference. The type of fracture does matter, though.