New blood test is good news, possible bad news for football

On the front page of Friday's USA Today  appears a story that could be very good news for football players. 

And very bad news for the sport.

The Army has discovered a blood test that reveals mild traumatic brain injury or concussion, via the presence of "unique proteins that spill into the blood stream from damaged brain cells."
"This is huge," Gen. Peter Chiarelli, the Army vice chief of staff USA Today.

And indeed it is.  If the test works, blood tests can be used to conclusively diagnose players who have had concussions -- at every level of the sport.