One of my players has a concussion.

She is itching to get back, and hates the thought that she may be out for the season, but she also admits that she is not feeling well. That means we have to be extra cautious, even more cautious than the doctors.

Who knew that concussions could occur in volleyball? I associate them with football, hockey and, as was shown most recently when David Wright of the New York Mets was hit in the head by a pitch, baseball.

But my player was sprawling to reach a ball, and as she did so she was struck on the top of the head by another player’s knee. I didn’t even know it happened, and she remained in the game, but hasn’t played or practiced since.

Here’s why we must be extra careful. As with so many other things, test results don’t tell you everything you need to know. Earlier this year every athlete in our school was required to take a baseline concussion test. After the injury, my player took the re-test, and the results seemed to look fine. But she still didn’t feel well.

So my question is: If the numbers seem OK, how long should any player stay out? Until they feel well, of course. But then for how long? Our school doctor says seven days after she feels well. But is that even enough? When you’re dealing with young athletes, you can scarcely be too careful.