Half Marathon training / 10k race

A quick question... I'm in training for the Royal Parks on 8th October. Training's going fine and I generally do my LSR on a Saturday morning. Next Sunday I'm doing a 10k race with a friend, to keep her company really- and for fun. That's not really enough distance to count as my long run and I'm not fussed about my time on the 10k. Do you think I'm still OK to do 10 miles or so the day before, on the Saturday? I don't want to mess myself up! I don't usually run every day altho through the week I may do 3 or 4 evenings on the trot with intervals / tempos/ around 4 miles if I can fit it into my work schedule.