Well, my muscle was pulled at the side of my calf not in the middle, however you can get referred pain with muscles. So you could have a sore muscle which you feel in a different place.
I would try this later. Lie on the floor, put the ankle of your sore leg on the roller and then cross your other leg over the top (it adds pressure).
The gently roll your leg left and right. If you feel any soreness, pause for 30 secs or so and then manipulate your ankle in circles which will help the knot ease as well. Then, in a sort of Z shape, move your leg down, so the roller moves up your calf. Then repeat. You might need to turn your leg quite a long way each time. You may not find any pressure points, and if not, the shoulder bridges should help.
There are loads of youtube vids showing you foam rolling. My PT taught me that a lot of them are rubbish, you always need to hold on a knot - just rolling back and forth aimlessly wont really help. It might be a bit ouchy, but don't forget to breathe to help the muscle relax. When you do get a spot that is sore and then you feel it start to ease, you will understand what you are looking for and can use it on your glutes and quads (without a doubt the most rewarding sensation in the world!)