NBA fortunes can change overnight.

Sometimes the stars align—literally, in a two- or three-star conglomerate—and an also-ran transforms into a top-flight title contender. That's the fun kind of basketball metamorphosis.

Not to drag the room down, but that's not the type of restructuring we're here to discuss.

Rather, we're focused on the other end of the spectrum: the rebuild.

It's one of the most daunting—and, if improperly handled, haunting—challenges in all of sports. It's a public admission that what you're doing isn't working and the formula is broken beyond repair.

For the following four teams, the 2021 offseason is the time to make that admission and get the ball rolling on an organizational overhaul.

Indiana Pacers

The Indiana Pacers are objectively...meh.

Heading into Sunday, they sat 19th in winning percentage (.473) and 16th in net efficiency (minus-0.3). After 2,670 minutes this season, they have scored 22 fewer points than their opponents.

Maybe those numbers don't immediately spark alarm sirens, but for a club that has made a pair of coaching changes amid a five-year run of first-round exits, the walls of mediocrity might have this franchise feeling claustrophobic.

How do the Pacers escape the NBA's middle class? Great question. The Circle City has never been a draw in free agency. Even if it was, Indy already has six eight-figure salaries on the books for next season and four $18 million-plus salaries owed for 2022-23.

Potential avenues for internal improvement are few and far between. Only three of Indy's rotation regulars are under the age of 25: Domantas Sabonis (who turns 25 in May), Aaron Holiday (who turns 25 in September and hasn't had a great season) and Goga Bitadze (who isn't averaging 10 minutes per game for his career).

Having a healthy T.J. Warren—who effectively lost this season to a foot surgery—would help some, but the next person who sees the Pacers as being a healthy Warren away from title contention will be the first.

The Sabonis-Myles Turner frontcourt isn't working (minus-1.1 net rating in 1,040 minutes). The lack of a superstar caps the team's ceiling and torpedoes even uber-optimistic title hopes. The prospect shortage means the outstanding issues won't fix themselves.

Unless the Pacers are content with making brief playoff cameos, it's time to change the formula. Trade a big, shed another big-money player (or two) and aim for the kind of draft picks or prospects who could eventually become the top-shelf talent this team doesn't have.

Portland Trail Blazers

This one is tough to write for a couple of reasons.

For starters, there aren't many more entertaining teams to watch than the Portland Trail Blazers when Damian Lillard and CJ McCollum have it rolling on offense. Considering that duo contributes more than 50 points per game between them, it happens more often than not.

Secondly, questions about a possible Blazers' blow-up have lingered for years and have always drawn the same response from the franchise: Ain't happening.