Achilles just tight or damaged?

I have had a tight Achilles in my left leg down just next to the ancle bone, tender when I squeaze it, tight when I streatch, when I get fully warmed up it seems to ease up and not hurt, but his requires jogging, streatching and jogging again and more stretching. It doesn't hurt to walk, just when I run during practice.

I am worried as I don't want to tear it or do futher damaged I still need to play as I am my soccer teams goalie and don't want to miss the beginning of the year, but I also don't want to miss the rest of the year with a rupture.

I have been taking Gluscosmine Chondroitine and MSM as I took it 5 years ago to heal a totally severed Patella Tendon in my other leg and was able to walk in less than a month with no crutches. I am hoping this will help me heal faster. I have been stretching gently when there is no pain, and resting as much as possible.

I really need some good advice on what I should do and how bad is it really? I am to optamistic?