WARSAW — For an industry based on human performance, you might think that the health of the participants would be paramount to the event. Your presumption would be misguided.

As Poland and Greece lined up in the host nation’s splendid new National Stadium on Friday evening, one watched and wondered how many of the players needed a painkilling injection to start the opening game of Euro 2012.

Perhaps Robert Lewandowski, whose goal-scoring form excelled throughout last season for his German club, Borussia Dortmund? Or Giorgos Karagounis, the 35-year-old veteran whose experience to Greece is so important after 117 previous games for his country?

We wouldn’t know even if both these players were shot through with drugs to control pain or inflammation. The injuries the players carry into big matches are trade secrets, the information masked from opponents just as the drugs — legally applied — are meant to mask the pain and discomfort of the individuals concerned.