Suggestions for balancing tennis and running

hey Guys. I signed up for my first ultra (50 miler) this May. I run cross country at College and since season ended I have been base building and such in preparation for this ultra. My question is do you guys have any suggestions in regards to balancing this with my tennis season? Tennis practice right now is at night 3 days a week indoors for 2 hours a day. While it is def not as much work as running, it still is physical so that combined with my running schedule is a lot to handle. This was my first week so far of practice and I have just not run on days of practice and will make up miles on Saturday and Sunday. Do you guys have suggestions on how I can slowly in cooperate miles on to tennis days. I just don't want to get burned out....
Thanks,
Ajrl56

The only thing I can suggest, is for you to run in the early mornings before classes on your tennis practice days. This may seem a lot, but remember you are wanting to run 50miles non stop. So more time you are on your feet, the better you are going to feel at race time.