Calf tightness can be one of the causative factors ofplantar fasciitis, your achilles tendon inserts onto your posterior calc at the same insertion as the origin of your platar fascia ligament. Generally stretching your calf will help (stretch both your gastrocs AND soleus, one being a normal calf stretch the other a "Knee to wall" stretch)
Example of gastrocs stretch
http://64.143.176.9/library/healthgu...hwkb17_077.jpg
Example of soleus stretch
http://www.sportsinjuryclinic.net/ga...stretch220.jpg
Do not push these into too much discomfort for your PF ligament. Just nice and easy and slowly progress them.
I am sure your physio will give you some good advice on fridayGood luck with it all.