Athletic Supplement???

<p>I played soccer for three years. Should I complete the athletic supplement in order for colleges to know I played a sport? And, I was told I need to send a letter from my coach. Here's the thing, I had three different coaches on different teams. Should I send the letter of my most recent coach? He also told me to write a letter for him to check and sign it. What should I write?
Thanks!!</p>