When you're shooting sports, fast moving objects can appear blurred because they’re moving constantly and at high-speed. While using a fast shutter speed will freeze a point in time for a superbly detailed shot, using a slower shutter speed can add a sense of movement and drama to a shot, which is really effective.
The shutter speed you need depends on a variety of things, but try 1/500s as a starting point for most fast-moving subjects.
Whether you choose to make use of creative blur (through a slower shutter speed) or not, it is important to keep your subject in focus. The EOS 7D Mark II has advanced technologies that predict your subject’s movement. iTR AF uses face and colour tracking to predict a moving subject's position. It then selects the correct focus point which helps you get a sharp image.