March Madness wouldn’t be March Madness without the excitement of those early upsets in the NCAA Tournament.

The 68-team field won’t be announced until Sunday, but it’s a safe bet that one or more high seeds will get bounced early.

Purdue was a 23 1/2-point favorite when it went out in the first round to No. 16 seed Fairleigh Dickinson last year — another in a line of tournament clunkers for the Boilermakers. Maybe it was because Purdue’s guards couldn’t make shots. Maybe Fairleigh Dickinson’s small lineup bothered the Boilermakers.

Kihei Clark’s memorably bad pass set up JP Pegues’ winning 3-pointer in No. 13 Furman’s upset of No. 4 Virginia last year, but the matchup did the Cavaliers no favors. Furman plays at a high tempo and spreads the floor. Virginia goes slow and its defense had difficulty guarding the perimeter, allowing Furman to stay in the game.

“The style makes the fight in how some of these things can happen if your strength combats the other team’s weakness and the other team is one of those higher seeds. That’s where you run into trouble,” said Field of 68 analyst and TV commentator Terrence Oglesby.

The odds of various teams winning the national title are fun to consider — as of Tuesday, injury-riddled blueblood Kansas is a 35-1 long shot, according to FanDuel Sportsbook, while San Diego State is 75-1 a year after crashing the national title game. Different season, different team.

Here are some projected high seeds that could be on upset alert the first weekend of the tournament:

ALABAMA

The Crimson Tide can win a scoring contest against anybody. The question is whether they can play enough defense to win a game if the pace becomes grinding, as often happens in the tournament. Mark Sears is one of the best guards in the country, and he leads the nation’s most efficient and highest-scoring offense. But they are 342nd out of 351 teams in scoring defense.

DUKE

First, the Blue Devils are among the teams fully capable of reaching the Final Four. They went into the ACC Tournament 8-2 in their last 10 games, and most of those wins weren’t close. But there’s been a drop in rim protection since Derek Lively II left after last season. There’s also been a late-season injury to freshman guard Caleb Foster — a part-time starter — that has left him wearing a protective boot on his right foot. A team with quick guards who can get to the basket could be trouble.

IOWA STATE

The Cyclones have been fabulous defensively in three seasons under T.J. Otzelberger, and they beat Houston, Kansas and BYU while going 18-0 at Hilton Coliseum this season. Thing is, almost half of those home wins came against weak nonconference opponents that inflated their NET ranking. The concern is if the Cyclones get a matchup against a team that takes care of the ball and has a big, physical guard.

KANSAS

Big 12 scoring leader Kevin McCullar, big man Hunter Dickinson and freshman Johnny Furphy headline a strong starting five. But McCullar tweaked a bone bruise in his knee and Dickinson dislocated a shoulder, and both will miss the Big 12 Tournament. That puts pressure on a bench woefully short of depth. The Jayhawks’ eight losses in conference play are their most since 1988-89, and a program that won it all just two seasons ago went 3-7 on the road.

MARQUETTE

Marquette is another example of how a late-season injury to a key player could be ruinous. Tyler Kolek has missed the last three games with a strained oblique and has been ruled out of the Big East Tournament opener Thursday. Coach Shaka Smart said Kolek will be available for the NCAA Tournament, but will he be 100%? The Golden Eagles are potentially great when he is fully healthy. They aren’t nearly the same otherwise. The best point guard in America is capable of scoring 30 points with double-digit assists any given night.

PURDUE

The Boilermakers seem likely to land another No. 1 seed and are on the list only because of their recent history: a first-round loss to No. 16 seed Fairleigh Dickinson in 2023, a Sweet 16 loss to No. 15 Saint Peter’s in ‘22 and a first-round loss to No. 13 North Texas in ‘21. They have been upset by a lower seed in six of their last 10 NCAA appearances. Still, this team is better than a year ago with Zach Edey again leading the way. Maybe this is the year Matt Painter makes it to his first Final Four.