When is your board? I asked my RSM about this, as I'm intending to get on Main Board over the summer. According to him, getting a date for Main Board isn't nearly as arduous as getting a date for Briefing and it's still possible to get on the MB in May (it may have filled up by now, but I heard this last week). To be honest though, I'd just call them up and hear it from the horse's mouth. They will be sympathetic if you have an injury and there is no point risking failing the phys as that is really the only part of MB you can actually prepare for and know you can pass.