Marcus Freeman -- Notre Dame lost because they believed hype - ESPN

After evaluating his team's shocking 16-14 home loss to Northern Illinois on Saturday, Notre Dame coach Marcus Freeman said on Monday that in addition to the mistakes the Irish made on the field, it was also clear his team needs to learn how to handle success.

One week after earning a statement season-opening win at Texas A&M and looking like a legitimate contender for the 12-team College Football Playoff, the Irish suffered one of the program's biggest upsets in decades, losing a game they were favored to win by 28.5 points.

«This is the first time in my three years as a head coach that we have won the big game early in the season,» Freeman said. «Two losses to Ohio State and then all of a sudden, we win and everybody says, 'Hey, you're going to the playoff. You've got an easy schedule.' We all hear it, and I think we started to believe that.

»There is a physical approach to preparing for a game, and I think physically we prepared the right way," he said, «but there's also a mental approach and a mindset that you have to have every single week, and I think that's where we failed.»

Freeman also pointed to in-game factors like losing the turnover margin 2-0, allowing six explosive plays for 186 yards while gaining five for 94 yards. NIU also won the time of possession, outgained Notre Dame on the ground, and was better on third downs.

Not since 1995 against Northwestern had Notre Dame lost a game it was favored by 28 points to win. The Fighting Irish entered Saturday with a 71% chance to make the CFP, according to the Allstate Playoff Predictor, and that sank to 24% with the loss.

Freeman, whose team will travel to Purdue on Saturday, said his team isn't focused on trying to run the table.

«That doesn't matter,» he said.