Did you not tackle each other in football practice? Did you not do "Bull in the Ring" or"Gauntlet" in practice?
Did you not scrimmage or run odd-man breaks in basketball practice?
Were you ever told to "get in front of it" and "knock it down" in baseball practice? Did your coach ever have you do sliding drills to work on hand-tag and hook-slides?
There's an inherent risk of injury. And there's a possibility of players going too far to impress the coaches in practices and preseason games. It happens. Perhaps not in tennis or golf, but this is a different beast than either of those two.
I think 2 games into preseason may be a bit too soon to start questioning the team's discipline. You obviously don't. Ask again after week 2 of the regular season, and I'll likely have a different answer. But not now, not yet.