Update: The players reportedly left the field due to a policy change that occurred two years ago (Notre Dame did not lose a home game last season) — apparently the student body didn’t get the memo:

Notre Dame spokesman says players began to head into tunnel after game due to policy change that players wouldn’t do alma mater after losses — JJ Stankevitz (@JJStankevitz) September 29, 2013

Earlier: This evening, Notre Dame suffered its second defeat of the season, falling to the Oklahoma Sooners 35-21. The loss obviously stings for the Irish, as it officially puts an end to any dreams of a return to the BCS National Championship Game.

The players, predictably, were very upset after the game. So upset that a large number of them decided to skip the postgame singing of the alma mater — a sacred tradition at Notre Dame, win or lose. As a portion of the team decided to “opt out” of ritual, boos cascaded upon them from the student body:

Ok football players? Just walk off the field without doing the alma mater… #ItsOk — Emma English (@Emma_English13) September 28, 2013

ND players going in the tunnel before the alma mater… That’s the biggest shame of the day — Mike Brown (@LikeMike025) September 28, 2013

Very disappointed in the @NDFootball players that did not stay for the post-game alma mater. We didn’t leave. We win and lose as a team. — Jennifer Sharron (@jensharron) September 28, 2013

Some real ugliness at end of #ND game. Students booing, players not staying for Alma Mater, Kelly screaming at fan #notgood — Brian Hartnett (@BrianGHartnett) September 28, 2013

The only thing more disappointing than the game is watching some of our players leave the field before the alma mater. Unforgivable — Adam Lamm (@therealadamlamm) September 28, 2013

#NotreDame players booed as they opt out of the postgame alma mater. — Andrew Owens (@BGI_AndrewOwens) September 28, 2013

Losses are certainly frustrating, but players in the past (including many on this team) found a way to battle through the pain to sing with the student body that supports them unconditionally. It’s easy to see why the students voiced their displeasure.