My hamstring injury from last year was tendinitis at the insertion point to my glute. The foam roller kind of helped, but what helped even more was a small massage ball or tennis ball. I more or less sat on the ball on the floor and rolled over the ball at the most tender spots. It hurts a lot as as do it, so be forewarned. Stretching also helps so long as I hold the stretch for at least a minute. My favorite is to lay on the floor with the injured leg extended straight up in the air and the other leg flat on the ground. Grab behind the thigh and hold or use a yoga strap around your flexed foot.