If you were shooting at your max aperture, then you can stop it down a bit. You don't have to shoot at f/2.8 to get good bokeh. If you stopped it down a bit more the focus range would be higher.
If you are not already, choose just the center focus point. Focus then recompose and shoot. If the subject is moving into OOF then try switching it into AI Servo (on canon).
If you do not have AI servo or don't have time to switch into it, then I zone focus (knowing what my DOF will be) beforehand and anticipate the shot. That takes a bit of practice but it works well. Hope that helps.