Cooper Flagg and the can't-miss NBA prospects who missed

Zion Williamson, Duke | 2019

Williamson was a household name even before his lone season with the Blue Devils, taking a freshman-heavy team to the Final Four. But a college game where Williamson blew out his sneakers and injured his knee was a bad omen for his future career.

Markelle Fultz, Washington | 2017

Fultz enjoyed a stellar season at Washington that made him the consensus top prospect, thanks to his size, athleticism and passing ability. The Philadelphia 76ers traded up to select him with the No. 1 overall pick, but Fultz suffered a mysterious shoulder injury that robbed him of his ability to shoot. Traded during his third NBA season, Fultz's career was further derailed by tearing his ACL at age 22. This season, he didn't sign with an NBA team until February.

Ben Simmons, LSU | 2016

Not unlike Fultz, the decline of Ben Simmons was a combination of injury and an inability to shoot. Simmons was considered a transcendent passer with great size and positional versatility, though observers were concerned with his poor shooting and perceived lack of effort.

Simmons made three All-Star teams from 2019-21, but he had serious shooting weaknesses. He refused to attempt three-pointers, and his poor free-throw shooting (59.2% for his career) caused him to avoid contact, most famously in a Game 7 playoff loss to the Atlanta Hawks. Then, Simmons refused to play for the Sixers and Nets. Thanks to his refusal to play and various injuries, he played only 107 games in his ages 25-28 seasons.

Michael Beasley, Kansas State | 2008

Beasley had one of the most statistically-impressive seasons for any college freshman in 2007-08, averaging 26.2 points and leading all of college basketball with 12.4 rebounds per game. It was a serious debate between Beasley and Derrick Rose for the first overall selection, but Beasley went No. 2 to the Miami Heat.

Things started badly. Beasley was fined $50K for breaking rules at the NBA's Rookie Transition Program, involving female guests and marijuana. After two seasons with the Heat, Beasley showed he could score, but he didn't pass, play defense or rebound in the NBA. Miami let him go after two seasons to clear salary space to add LeBron James and Chris Bosh. Putting up 19.2 points per game for the 17-win Minnesota Timberwolves in his third season was the high-water mark for Beasley, who was later released by the Phoenix Suns after an arrest for marijuana possession.

Greg Oden, Ohio State | 2007

Oden led Ohio State to the NCAA final in his freshman year, losing the title game to Florida's dominating future NBA stars Al Horford and Joakim Noah. But he missed his rookie season after the Portland Trail Blazers picked him No. 1 overall after microfracture surgery. 

And he just kept hurting his knees. He hurt his kneecap late in the 2008-09 season. After 21 excellent games in 2010-11, Oden fractured his patella. Then, another microfracture surgery cost him the next season, and the next. He returned to play 23 games for the Miami Heat in 2013-14, with his career ending just after his 26th birthday.

Whoever drafts Flagg needs to make sure he keeps improving his shot. But most of all, they need to protect his knees.