I've had it before, and it normally goes in weeks. Physio usually tells you RICE, and a tennis ball. You're to sit there all day, rolling the ball in and around the arch of your foot with as much weight as you can bear, and it will massage the area and stretch the band.
Those of you sending him your best wishes, believe me it's not life threatening, it's hardly even painful, just a bit of an irritation, and he's also a millionaire, so he'll be alright I reckon.
I know people that have ran marathons with it.