So much is going right for Michigan State.

An offense that averages 45 points per game, a team that has 12 straight wins over conference foes and a defense that is annually one of the nation's most formidable.

Yet cracks are beginning show.

"We just have to continue to keep our foot on the pedal and not get lax and not get laid back, just continue to execute," receiver Tony Lippett said Saturday after the Spartans nearly blew another big lead in its 45-31 victory over Purdue. "We have to finish every time we come out there. As an offense, we try to finish every job."

The Spartans (5-1, 2-0 Big Ten) may have the most complete team in the conference.

Quarterback Connor Cook is improving in his second season as the starter, the rushing game has provided a strong counterbalance to Cook & Co. and the defense keeps forcing turnovers and pressuring quarterbacks while cracking down on the run. The combination has turned the defending Rose Bowl champs into conference favorites and perhaps the league's best chance to play in the inaugural college football playoff.

But there's one big difference between this year and last: The Spartans are playing an increasingly risky game.

After taking 20-plus point leads into the fourth quarter last week against Nebraska and Saturday at Purdue, Michigan State has had to scramble late just to hang on.

Michigan State has been here before. In 2012, the Spartans finished fourth in the Legends Division after losing five Big Ten games by a combined total of 13 points. Last year, the Spartans won all eight regular-season conference games by double digits before beating undefeated Ohio State 34-24 in the Big Ten championship game.

What needs to be fixed?

"I wish I could tell you about that," center Connor Kruse said. "All I know is this week's focus was about finishing strong."

That's not likely to change next week. Michigan State is at Indiana (3-3, 0-2), a team capable of scoring in bursts. A left shoulder injury could keep starting quarterback Nate Sudfeld out of the game, though the Hoosiers still have one of the most dynamic runners in the country in Tevin Coleman. And the up-tempo offense that makes no lead safe, the short-handed Hoosiers just might take a page out of Purdue's game plan with a new, young quarterback behind center.

The Boilermakers entered Saturday No. 13 in the Big Ten in total offense and No. 8 in rushing offense. But they challenged Michigan State with a steady diet of screen passes and quick-hitting runs, had a chance to force overtime after getting the ball back with 2:57 left in the game. Purdue ran for 162 yards, but the Spartans this season gave up their second-highest point total of the season and allowed Purdue to cut an 18-point first half lead to seven and a 21-point fourth-quarter to lead seven.

"We were playing too much in space. Those things need to be covered and we needed to execute better," Spartans coach Mark Dantonio said, explaining why the defense struggled so much in the first half. "We just played better (in the second half), we adjusted some things formationally and adjusted some things coverage-wise, but we tackled in space better and got off blocks."

Purdue might have provided a template for future opponents. The Spartans prepare for a second half that features Ohio State, Maryland and Michigan.

While Dantonio doesn't sound too concerned, at least publicly, he believes the challenges are making Michigan State a tougher team.

"Do we want to win by 28 points? Yeah," he said. "But credit what the other team does, and then we continue to play through and continue to fight."