After your warmup you doing drills and strides? Not to somehow imply you did something wrong, just trying to be helpful. Injuries sometimes just seem bound and determined to happen. Lately knock on wood I seem to have staved them off, starting w light stretching and walking as soon as i get out of bed, warm shower w pt moves and massage, then the whole warmup routine....sorry about your injury.
I did everything exactly the same as I usually do, including drills and strides; just felt sluggish as indicated by the first rep at 47; I think my body was just not used to a late afternoon Fri workout; I had that terrible Riverfront Mile run on a Friday pm; I should just forget intense workouts on Fri pm; Fri am seems OK, just unlucky my main track and the backup track were busy at the time.