Bad Calves

I don't know if I'm just getting older and the body isn't working like it used to, but I keep straining or pulling my calf muscles. The last few months I've lost a fair amount of weight, gotten in pretty good shape, given up caffine, hardly drink the booze anymore, and am eating healthier than I have in years.
I will admit that the last few years just about everything on my body hurt, so just having calf problems is better than where I was. But I don't get it? I can run on the treadmill in the gym for an hour without any problems. I usually run on it 3-4 times a week, sometimes for an hour, other times just for 20 minutes as a warm up. Granted I do stretch before hand.
But then I also run around Green Lake a couple times a week and every time my calves get tight. It's one, the other, or it's both. Whenever I run outside on uneven terrain, I get flat tires. While I'm running I can feel them stiffen up and tighten. I stretch before I run just like I do at the gym.
Same thing has been happening when I play soccer on Thursday nights. So last night we had our first game in awhile (they keep getting canceled due to frozen, snow covered fields) and sure enough I had to leave the game in the middle of the second half. I'm dribbling with the ball into the corner, I cut hard and cross the ball. Right when I cut I felt almost a 'pop' or the tear of the muscle. Shortly afterward, it felt like I had a softball for a calf muscle. Done for the night. Went home, grabbed the ice, the Advil, and the remote control.
I've been making an effort for months to stretch my calves and increase my flexibility but it must not be working. AAaarggghhhh. Is this what happens when you get older? I sure hope not.
Oh they aren't cramps in my calves either. I am pulling the muscle over and over again. Both calves. It hurts right where the diagram is pointing. So it goes I guess. I've participated in sports my whole life with injuries and can hardly remember something not being out of whack. I'm just so close and actually making an effort that its discouraging. If anybody has advice I'm all ears.