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Kristaps Porzingis first felt the pain again in December. In a game against the Nets, the Knicks star hobbled around the floor and then finally motioned to the bench in the third quarter after experiencing what he called a "sharp pain" in his left knee. It was the same knee that caused him to miss time at EuroBasket last summer.

Porzingis took a week off, and in his first game back, he shot 0-of-11. After losing a back-to-back set in which he shot 10-of-32 less than two weeks later, Porzingis admitted to reporters, "I'm tired, I'm tired, I'm so tired right now."

But he kept on playing. He tweaked the knee again during a late January practice, forcing him to miss another game. Two weeks later, Porzingis would suffer an injury from which there would be no return this season, tearing the ACL in his left knee after a thunderous dunk over Giannis Antetokounmpo.

The play was symbolic of this 2017-18 season. A breathtaking move by one of the league's most exciting talents, the sort of spectacular athletic display that has NBA executives, league partners and fans drooling for more, only to be followed with a heart-wrenching injury that knocks yet another star out of the picture, filling Twitter timelines and national airwaves with widespread grief. Yet again.

This season has seen DeMarcus Cousins tear his Achilles tendon after a stretch of abnormally high minutes, John Wall sidelined for what is projected to be two months after a scope on his left knee, which had already cost him almost a dozen games in November and December, and Kevin Love break a bone in his hand, forcing him to miss two months as well.

But the injury spell goes well beyond that.

Andre Roberson, Isaiah Canaan, Gordon Hayward, Mike Conley and Seth Curry are just a few more whose seasons have come to an early end because of injury.

Gerald Herbert/Associated Press/Associated Press/Associated Press

So far, the number of injuries and the total games lost because of them have risen significantly compared to seasons past.

Through last Friday, there were 3,798 games missed due to injury, up 42 percent from the same portion of games last season, according to injury-tracking website ManGamesLost.com. That echoes the research of injury tracker Jeff Stotts of InStreetClothes.com, who noted in late January that the NBA reached 3,000 games lost due to injury about a month faster than it did last season. And that was before Cousins, Roberson and Porzingis went down for the year.

By some teams' estimations, games lost due to injury could skyrocket to a 50 percent increase by season's end compared to 2016-17. Remember, the Porzingis injury has only just begun to count toward that total.

So what's behind this? Bad luck or something else?

The effect of a shorter preseason

Part of the problem could be plain old randomness at work, an unfortunate byproduct of having 7-footers run and collide with each other 1,230 games a year.

But many executives and coaches have wondered how the new stretched-out schedule has affected readiness to perform at a high level. In an effort to reduce back-to-backs, the NBA decided to shorten training camp by seven days and cut the number of preseason games, time that is normally reserved for conditioning and regular-season preparation.

Some execs are convinced that the decision has backfired, resulting in an uptick in leg injuries in the early going.

"That's absolutely because of the shortened preseason," said one top executive from a Western Conference team, who requested anonymity due to sensitivity of the topic at the league office.

To increase the amount of rest time built into the season, the NBA decided not to reduce the schedule from 82 games despite calls to do just that in years past from stars such as LeBron James, Kobe Bryant and Dirk Nowitzki. Instead, the NBA, with the players union's blessing, pushed the regular season into what once was the preaseason, slicing training camp time and exhibition games.

Alex Brandon/Associated Press/Associated Press

Before the season, the move to accelerate the season's kickoff was largely applauded by coaches.

"We've been lobbying for less preseason games for decades," Mavericks head coach and president of the National Basketball Coaches Association Rick Carlisle told NBA.com in October. "I applaud Adam [Silver] and Michele [Roberts] for coming up with a model that's going to work. It's going to work extremely well."

The results have not been encouraging. Chris Paul, who is the president of the players union, has missed nearly 20 games due to groin and knee issues. Former MVPs Stephen Curry and Kevin Durant have missed stretches. Perennial MVP candidate Kawhi Leonard's quad has sidelined him for all but nine games. Blake Griffin's balky knee cost him 14 games before the Clippers shipped him off to Detroit.

Former Milwaukee head coach Jason Kidd told NBA.com in mid-October that the shortened preseason schedule was "too fast" for his team. "I understand they want to give the players rest but they're trying to smash training camp into three weeks," Kidd said. "There's just too many injuries throughout the whole league."

Not everyone is quick to blame the schedule. The Warriors' Steve Kerr watched Curry go down with a bad ankle turn late in a Dec. 4 matchup against the New Orleans Pelicans on the second night of a back-to-back. The injury came after a preseason trip to China made for an even shorter training camp than other teams, which Kerr believes set the team back in terms of conditioning.

But to Kerr, Curry's injury was a fluke, not a schedule-related bad blow.

"I know injuries are up overall around the league, but whether that's due to the schedule is pure speculation." Kerr tells B/R. "I think the schedule is definitely good in terms of cutting back the load of back-to-backs and four-in-fives. But I didn't feel like we were ready for the first two weeks of the season because of [the shortened preseason]. How that affects injuries I have no idea."

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Pistons coach Stan Van Gundy told NBA.com he entered the season "rushed" as a result of the reduced preseason. "They're doing the best they can in the league office," Van Gundy said of the changes. "Whether that is a benefit or not, we're going to find out."

Mike Budenholzer, now in his fifth season as head coach of the Hawks, also felt the effects of a quickened preseason, though he didn't think it was a major issue with his young team.

"I feel it did limit what we could do as far as readiness, both conditioning and game prep," Budenholzer told B/R. "I'm still a fan of shortened preseason, though. All of us will better understand and adjust next year."

The NBA isn't the only league wrestling with how much preseason players and teams need to be ready and healthy. The NFL's latest collective bargaining agreement, signed in 2011, called for strict limits on offseason practices and reduced the amount of hitting allowed in practice.

Not everyone agreed with the move.

"Personally, I think that's taking the wrong approach," New England Patriots coach Bill Belichick said in 2013, according to the Associated Press (h/t New York Times). "You have a gap between preparation and competition level. And I think that's where you see a lot of injuries occurring. We get a lot of breakdowns. We get a lot of situations that players just aren't as prepared as they were in previous years, in my experience anyway."

Pace and space

It's impossible to ignore how the advances in the way basketball is played and players train year-round have contributed to wear and tear.

The NBA is playing faster than it has in over two decades, as pace has increased in each of the last six seasons. It's hard to pinpoint exactly how much the helter-skelter style of play has influenced injury rates, if at all. But each game packs more trips up and down the court and quicker turnarounds than we have seen since Gary Payton was a rookie.

"Of all the sports we study, elite-level basketball is the most demanding, period," says Dr. Marcus Elliott, who runs P3 Peak Performance in Santa Barbara, California, a training facility that many pro athletes visit. "There are still players who rely overly on the preseason to get into game shape. With so much of the sports science conversation in the NBA focused on rest and player load, I worry that players may equate offseason rest with longevity."

The offseason could also be a factor. Orlando coach Frank Vogel told the San Antonio Express-News in November that he felt many of the early injuries could be explained by rigorous offseason programs and shortened time off.

"It used to be you had to beg guys to work out in the summertime," Vogel said. "Now you have to beg them to pull back. Then you go through an 82-game season after double- and triple-sessions every day during the summer. … These guys' bodies can't handle it."

Steven Senne/Associated Press

Diagnosing when a player is most susceptible to injury has become as tricky as understanding why a player is injured.

Teams across the league have increasingly adopted the use of wearable devices geared toward injury prevention, but that has its limits.

In a new study published in the scientific journal PLOS ONE, a group of researchers—including two San Antonio Spurs sports science staffers—found that a popular wearable device in NBA circles, made by an Australian company called Catapult Sports, may not be as accurate as the company claims it to be, calling into question the validity of the information teams use for the conditioning and training of athletes. The Catapult device was among the list of wearable technology approved by the league and the players union in the 2017 NBA collective bargaining agreement. (However, the effect on injury rates may not be massive considering wearables are still banned from in-game use.)

Indeed, accurate data collection can prove slippery at times. New league rules policing strategic rest during marquee games have mitigated a host of DNP-Rest designations used in the past few seasons. Per the ProSportsTransactions.com database, incidences of games missed due to a listed "rest" have decreased by about 34 percent this season (51 DNP-Rests compared to 77 at this point last season). A team looking to rest a player could simply list a dummy injury in order to sidestep punishment from the league, fudging the injury data.

When it comes to data analysis on injuries, much depends on timing. For instance, if Hayward and Jeremy Lin suffered their injuries on the last game of the season instead of the first game of the season, the man games lost due to injury would count as zero instead of 162 combined. Furthermore, offseason injuries like those suffered by Leonard and Phoenix's Brandon Knight have spiked the totals even though it isn't a result of the in-season schedule.

Still, when you turn on your TV and Steph Curry is in a sport coat and not a uniform, that's hard to miss, though it hasn't been as bad for business as the league might have feared.

Changes ahead?

Here's the good news: Despite all the absences from star players, ratings are up about 20 percent, according to ESPN's Darren Rovell.

Consider the battered Christmas Day lineup. Five high-profile stars—Curry (ankle), Paul (groin), Isaiah Thomas (hip), Hayward (ankle) and Derrick Rose (ankle)—were all spectators on Christmas Day. (For those doubting Rose's star power, he ranked top 15 in jersey sales last season). All in all, 30 percent of former All-Stars on Christmas rosters didn't take the court that day. And that doesn't account for Lonzo Ball, who didn't play on Christmas and has been sidelined for 19 games this season due to injury.

The audience didn't seem to mind the no-shows too much. According to an ESPN press release, ESPN and ABC's NBA Christmas ratings were up 39 percent compared to last year.

Julie Jacobson/Associated Press/Associated Press

While it's true that injuries and ratings haven't been moving hand-in-hand this season, the greatest predictor of injury is prior injury, which means this problem won't likely be going away anytime soon.

Shortening the season from 82 games, an idea that has long been a nonstarter with league owners, is a lever that could be pulled down the line. Interestingly enough, Commissioner Adam Silver has softened the NBA's stance on the issue and appears to be open to tightening the number of games.

"There's nothing magical about 82 games," Silver said in October, per Sam Amick of USA Today. "It's been in place for 50 years, but for the long-term planning of the league, as we learn more about the human body and the wear and tear of travel and the competitive landscape...invariably we'll look at the regular season."

While owners may fear a drop in revenue with fewer games, perhaps they'd be willing to reconsider their stance now that franchise valuations have skyrocketed.

The league's heart was in the right place when it reduced back-to-backs at the expense of preseason and training camp. But something seems to have gone horribly wrong along the way. As player absences blow past previous norms and All-Stars break down, the NBA has to take a hard look at how to ensure a healthier league going forward.

Tom Haberstroh has covered the NBA full time since 2010, and joined B/R Mag after seven years with ESPN as an NBA insider and analytics expert. Haberstroh is also a co-founder of Spotlight Media Ventures and regularly hosts The Basketball Friends podcast for the Leverage The Chat multimedia network. Follow him on Twitter: @tomhaberstroh.