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 legitimate contenders 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. "This week matters. Who cares about the rest of that stuff, man? We've got to take care of this week, and that's got to be our mindset."

Notre Dame quarterback Riley Leonard completed 20 of 32 passes against NIU for 163 yards, two interceptions and no touchdowns. Freeman said that he never considered switching quarterbacks in the game and that the staff has "a lot of belief in Riley and him running our offense."

"There are times that he has to throw the ball better," Freeman said. "He knows that, and his fundamentals have to be better. His decision-making has to be better, but we also have to be better around him. That's coaches, and what we're asking him to do and what we're asking him to read. We've got to catch the ball when he throws it. We've got to be better on contested catches. There're fingers at everybody. We're pointing our finger at everybody."

Notre Dame entered this season with a young offensive line that had a combined six career starts, and Freeman said he saw progress from the group over the past week. He said that there was good protection but that there has to be trust to step up "and make those throws."

Freeman said starting wide receiver Jordan Faison, who injured his ankle at Texas A&M, is expected to return to practice Tuesday and will be available against Purdue.

Notre Dame has yet to string together more than five consecutive wins under Freeman, who is entering his third season. He said he didn't have an answer as to why Notre Dame has struggled to find consistency.

"That's the ultimate challenge," he said. "And every year presents a different challenge. ... That's why it took me a little bit of time to look back and say, 'OK, what do we have? What do we have to learn from this game? Yeah, schematic things we've got to fix, but here's what's different about this one, is that we've got to handle success the right way."

"I know we'll get it right," he said. "... We have the people in that building to make sure we get this thing where it needs to go."