A method of manufacturing a fluid-filled chamber may include utilizing one of a blowmolding and a thermoforming process to define a first surface, a second surface, and a sidewall surface of the chamber. An aperture is defined through the first surface in a location where the first surface is spaced from the second surface. A pressurization apparatus is located adjacent to the first surface and around the aperture, and the pressurization apparatus is utilized to inject a fluid into the chamber through the aperture, compress the first surface against the second surface, and form a bond around the aperture and between the first surface and the second surface.