The Louisiana State University men’s basketball coach blew his whistle frequently as his team performed a defensive drill. Usually he would demand that the defenders in the one-on-one exercise put their body on the shooter and box him out rather than crash the rim.

Later, the team shuffled laterally in a set pattern, crisscrossing the court, each player slapping the coach’s hand near a 3-point line. There were water breaks lasting exactly two minutes. Eventually, there was a five-on-five scrimmage.

The scene at the Tigers’ Pete Maravich Assembly Center was as mundane as any basketball practice on any college campus — except for one aspect: In two rows on the side of the court, several dozen men sat, watching, taking notes, jabbing at their phones. Placards identified their affiliations: the Portland Trail Blazers, the New Orleans Pelicans, the New York Knicks.

Representatives from 28 of the 30 NBA teams watched the Tigers at specially designated open practices geared toward professional scouts last week. Weeks before the college basketball season begins in earnest, LSU’s players had what might be their most important performance of the year.

The event was part of a small but growing trend. Nevada-Las Vegas recently held a practice for NBA officials expressly designed like the NBA scouting combine. Kentucky, whose team last year produced four first-round draft picks — three of them freshmen, including the top pick, Karl-Anthony Towns — had its NBA-geared practice shown on ESPNU this month for the second year in a row.

“What the heck are we doing here?” ESPN’s Doris Burke asked her fellow analysts at the beginning of the broadcast, underlining its bizarre quality.

NBA scouts were drawn to LSU because of three players who are expected to land on NBA teams next season: Ben Simmons, a 6-foot-10 freshman from Australia who is a projected top-three draft pick; the junior guard Tim Quarterman; and the freshman Antonio Blakeney.

“It’s everybody’s goal and dream on the team to go to the NBA, so that was a big deal for us,” Quarterman said.

The trend is emblematic of college basketball’s raison d’être, at least among the basketball powers. Teams want the best players. The best players’ main interest is getting to the NBA, which they may do in as little as one year after high school (but not sooner). Therefore, to succeed, coaches must sell the future.

“It’s always been implicit,” said Shane Battier, who played at Duke before a long NBA career and is now an ESPN analyst. “Now it’s more celebrated and less taboo.”

No coach has taken advantage of this paradox better than John Calipari, whose Kentucky teams have made four of the past five Final Fours while producing 18 first-round draft picks since 2010. Other coaches took note when he staged an open practice last year.

“We have to all come to grips with the fact that literally just about every kid comes to college thinking they may not be in college for four years and are going to put their names into the NBA draft,” UNLV coach Dave Rice said.

“You’re coming here to help us win basketball games, but at the same time it’s equally important for us for you to be able to maximize your pro potential while you’re here,” he added.

Having an open practice signals to future prospects that a program understands this.

“To have a combine and invite the pro scouts in, that says to the kids, ‘Look, you have a college connection,’” Battier said.

The one-and-done phenomenon, in which the best players compete in college for one season before declaring for the NBA draft, looms over the college game and has, some say, merely shattered what was previously the pretense that many top college players were primarily interested in winning an NCAA championship.

“They asked about this combine — why did we do it?” Calipari said on ESPNU. “‘Why would you have your kids thinking about the NBA at the start of the season?’ They all are! Not just my guys, everybody’s guys.”

In Kentucky’s case, the practice also provided two hours of nourishment for Big Blue Nation’s insatiable, year-round hunger for Wildcats basketball. Calipari was wired for audio, and the program periodically cut to him instructing his players. He and several players were interviewed.

The TV audience, a relatively modest 100,000 viewers, was nearly twice that for last year’s practice. Some fans, via social media, expressed enthusiasm.

“Love watching #UKPractice!” one said on Twitter. “So excited for the season! #BBN” (followed by a blue heart).

The point is not simply to let NBA team executives see the college players up close. After all, they are typically welcome at practices and games throughout the season.

“What people don’t understand is, we’re here every day,” said Austin Ainge, the Boston Celtics’ director of player personnel, who watched LSU last week. (NBA officials are prohibited from commenting on most college players.)

But there are practical merits to holding a dedicated open practice. The colleges put players through motions they will need to do again at the spring’s NBA combine; at UNLV, players will even have their wingspans measured. If a proposed NCAA rule passes in January, then, for the first time, certain underclassmen will be allowed to participate in a combine and still be able to decide not to enter the draft.

In the meantime, scouts get a preseason baseline and players gain experience.

Coordinating a day for scouts enables teams to raise the dial on activities scouts favor and eliminate ones that are unhelpful to them.

“They ask us what we’d like to see, and they do it,” said Ainge, adding that if a scout stops by a random practice, he is taking a gamble. “Could be a scrimmage, could be a day when they’re learning zone defense for 45 minutes.”

Johnny Jones, the LSU coach, said he had his players scrimmage more than they otherwise would have, for the benefit of the scouts. Quarterman, who had been practicing with the first team, switched his jersey from purple to gold to make a more even matchup.

Jones also said he planned to restrict NBA officials at most future practices until the regular season begins in mid-November, to limit distractions — which is a lot easier to do after giving those officials two dedicated days to come watch.

Keeping players focused on the current season rather than future ones is a chief challenge for coaches. Jim Haney, executive director of the National Association of Basketball Coaches, said: “Our guys — and they’ve done a good job on this — have had to strike the right balance. You have to be concerned about getting your degree. Even if you are a one-and-done, you have a responsibility to meet your obligations to be on this team.”

During practice, LSU’s players did not appear to be unusually engaged. There were moments of early-season sloppiness. Simmons, the most coveted prospect on the court, seemed serene. Asked before practice how he felt about the scouts’ presence, he shrugged.

“To me, it’s another practice,” he said. “I don’t think it really matters what school you pick. Sometimes, maybe with a few players, but for me I believe if you’re good enough, you’re going to go.”