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

A week after earning a season-opening blowout victory at Texas A&M that made them look like serious contenders for the 12-team College Football Playoff, the Irish suffered one of the team’s biggest upsets in decades, losing a game they were favorites to win by 28.5 points.

“This is the first time in my three years as head coach that we’ve won the big game this early in the season,” Freeman said. “Two losses to Ohio State and then all of a sudden we win and everyone says, ‘Hey, you’re going to the playoffs. You have an easy schedule.’ We all hear that and I think we’ve started to believe that.

“Preparing for a game requires a physical approach and I think physically we prepared properly,” he said. “But you also have to approach it mentally and have a certain mindset that you have to have every week and I think that’s where we failed.”

Freeman also pointed to factors during the game such as losing the turnover differential 0-2, allowing six explosive plays for 186 yards and five plays for 94 yards. NIU also won time of possession, outperformed Notre Dame on the ground and was better on third downs.

Notre Dame hadn’t lost a game in which they were favored by 28 points since 1995 against Northwestern. According to Allstate Playoff Predictor, the Fighting Irish had a 71 percent chance of making the CFP on Saturday, and that dropped to 24 percent with the loss.

Freeman, whose team travels to Purdue on Saturday, said his team is not focused on leading the standings.

“It doesn’t matter,” he said. “This week is important. Who cares about the rest, man? We have to worry about this week, and that has to be our attitude.”

Notre Dame quarterback Riley Leonard completed 20 of 32 passes against NIU for 163 yards, two interceptions and no touchdowns. Freeman said he never considered changing quarterbacks in the game and the team has “a lot of confidence in Riley and his role as the leader of our offense.”

“There are times when he needs to throw the ball better,” Freeman said. “He knows that and his fundamentals need to be better. His decision making needs to be better, but we also need to handle him better. That’s the coaches and what we’re asking him to do and what we’re asking him to read. We need to catch the ball when he throws it. We need to be better on contested catches. We’ve been threatening everybody. We’re pointing fingers at everybody.”

Notre Dame entered this season with a young offensive line that has made six career starts, and Freeman said he saw progress from the group last week. He said they were well protected, but that you have to have confidence to “step in and make those throws.”

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

Notre Dame has yet to win more than five games in a row under Freeman, who is entering his third season, and he said he has no answer as to why Notre Dame is struggling to find consistency.

“That’s the ultimate challenge,” he said. “And every year brings a different challenge. … So I needed some time to look back and say, ‘OK, what do we have? What can we learn from this game? Yes, schematic things we need to get right, but here’s the thing about this game: We need to handle success the right way.'”

“I know we can do it,” he said. “… We have the people in this building to make sure we get this thing where it needs to go.”