Kids interactions

Does anyone else worry during playdates that their kid(s) will accidentally hurt other kids? My boys are rough and for that reason (and the fact that we have no friends closeby) we've had no playdates except for my older son (4.5y). The other boys are 3.5 and 2. My 3.5 especially is very physical, a twig, but still very physical in his play. And yes, it's something I'm constantly working on for them to play nicely and gently.