You'll need to take emotional risks to understand how he feels. Don't be too reluctant to do so. The worst that could happen is that he doesn't share your feelings and it's a little awkward. Rejection has happened to us all. Don't dwell on it before it happens.
Read the following article, "How to Know When You Have a Crush" http://hub.me/an6SK. It describes signs of a crush both in oneself and in another person. Does he display some of these signs? The fact that friends see the signs seems to indicate that they see the signs. Ask them what specifically makes them suspect that he has a crush on you (the behaviors).
Next, read the article, "How to Tell Your Crush That You Like Them" http://hub.me/an3Lf for advice on how to share your feelings with him. Good luck!