The Jazz rampaged to a 19-10 record after the trade deadline by transforming, on a dime, from one of the league’s five worst defensive teams into its stingiest. Two lineup changes happened right before the Jazz took off: Utah traded Enes Kanter, opening a starting spot for Rudy Gobert, a.k.a. the Stifle Tower, and Quin Snyder swapped Dante Exum into the starting lineup over Trey Burke.

Exum tore his ACL on Tuesday while playing for the Australian national team in an exhibition game against Slovenia, quickly undoing one of those changes. The news is sending Jazz Nation into a panic and apparently jeopardizing Utah’s status as everyone’s favorite “Cinderella” playoff contender that isn’t actually a Cinderella at all. This injury will almost certainly cost Exum the full 2015-16 season.

Exum didn’t do much last season, but he gave the post-Kanter starting lineup some structural integrity. He enveloped opposing point guards on defense, and mostly stood out of the way on offense. Burke is too small to envelop anyone other than Isaiah Thomas, and he’s the worst kind of gunner — a point guard who shoots a lot even though he has never hit even 40 percent from the floor in the NBA. Reinserting Burke would seem to upset the fragile alchemy Utah stumbled upon by surrounding Gordon Hayward and Derrick Favors with defense-first, low-usage players.

And this is where we have to chill. Exum’s injury is a blow, but Utah should still make the playoffs as the no. 7 or no. 8 seed — or at the very worst, lose out to Phoenix in a spirited race for that last spot. It’s hard to untangle the impact of two simultaneous lineup changes that carried the Jazz over a small sample, but Utah’s rise was more about Gobert than Exum. It was all about defense — the Jazz offense declined by a tick after the All-Star break — and the team hummed on that end basically whenever Gobert was on the floor. The team’s most common post-deadline starting lineup with Burke in Exum’s place outscored opponents by 19 points per 48 minutes, and the Jazz surrendered just 99.7 points per 100 possessions for the season when Burke and Gobert shared the floor — the equivalent of San Antonio’s no. 3–ranked defense.

Gobert was incredible, and the guy he replaced wasn’t just a bad defender. Kanter might have been the very worst defensive player in the league among regular rotation guys.

Exum couldn’t really do anything on offense, save for chill in the corner and knock down wide-open 3s when his defender abandoned him to help on a more urgent threat. And, boy, did they abandon him. Exum had one of the lowest “gravity scores” among every player who took the floor last season, per SportVU data provided to Grantland, meaning defenders strayed far from him.

He shot miserably from deep when a defender was within even 6 feet of him, per NBA.com, and hit a blah 34 percent from the corners overall.

Knowing your lane has value — to a point. Exum not shooting also meant Burke was not shooting, and the difference is that Burke shoots a lot. Playing Exum meant that Burke’s bricky off-the-bounce jumpers became Hayward drives, Gobert dunks, Favors cutting scores, and other good basketball things. Exum showed all the yips on defense we’d expect from a dude who turned 20 just last month, but he’s legitimately giant for a point guard, and his length created problems on some nights.

Utah will be incrementally worse on defense with Burke in Exum’s place, and the trickle-down effect means many more minutes than expected for Raul Neto and Bryce Cotton — total unknowns at this level. This will all hurt, but hopefully not enough to really change Utah’s fortunes for next season.

The Jazz late-season formula might not have sustained at the same level over the course of a full season. The starting lineup of Exum, Hayward, Joe Ingles, Favors, and Gobert managed just 97.4 points per 100 possessions — not enough to survive long-term, assuming Utah’s defense settles in at “very good” instead of “insanely, historically great.” That group scored a bit better after the trade deadline, but in the long run, it might have needed some off-the-dribble juice that Exum was unready to provide.

Last season Exum might have been the worst pick-and-roll ball handler in league history. He shot 15-of-58 out of that play, and turned the ball over on 46 percent of the pick-and-rolls he finished — the highest qualifying individual rate ever recorded in the Synergy Sports database, which dates back to 2004. He dribbled around picks just fine, but once a help defender would block his path, Exum would melt into a puddle of panic. He picked up his dribble too early, or too late, mistimed passes, heaved the ball 10 feet over the head of his target across the court, and generally vomited away possessions. He looked off open players and threaded no-chance-in-hell passes to covered ones. He had no midrange game.

In other words: He was a teenager playing in the NBA. He’d have been better this season, perhaps in part because playing for the Australian national team gives him reps in a larger scoring role. Utah doesn’t need him to run the show — that’s Hayward’s job — but it does need a secondary creator who can keep the offense flowing after Hayward drives into the paint, bends the defense, and kicks the ball out. Any healthy offense needs that.

Burke is a craftier driver than Exum, and he actually shot 38 percent on spot-up 3s, per Synergy Sports. He’s awful shooting off the dribble, but Utah might achieve better two-way balance if Burke accepts a less ball-dominant role on offense. That’s on both Burke and the coaching staff. This isn’t Michigan anymore, and Burke’s track record so far in the NBA is borderline disastrous. He perked up late last season as a score-first option on bench units, but that mentality may not translate well in the starting lineup.

Ingles’s place in that lineup is fascinating, especially with Alec Burks returning from injury. Ingles is a smart passer who can run an emergency pick-and-roll, but he prefers to hang out on the perimeter and whip the ball around the floor. He doesn’t have the wheels on defense to stick with good NBA wing players.

Burks and Rodney Hood are interesting options if the Jazz want to transition Ingles into a bench role — as they did for parts of last season’s stretch run. They can do damage off the dribble, and both of them are more capable than Ingles at switching onto point guards in games when the Jazz might be able to hide Burke on a nonthreatening wing player. Hood shot nearly 37 percent from deep last season, and might prove to be a nice complement to Hayward on both ends. Shifting one or more active threats from the bench into the starting lineup wouldn’t leave the reserves without a showrunner, since one of Burks or Hood would still be around.

Between Burks, Hood, and a smarter use of Burke, the Jazz have options to cover over Exum’s absence. The very best option, of course, would have been Exum returning more prepared to contribute on both ends — especially on offense. Even in a long reel of Exum turnovers, you can see the outlines of an interesting ball handler. He has some fast-twitch explosiveness, and a thoughtful change-of-pace game. He’s not in a rush, but he can accelerate past suckers just when they think he’s about to pick up his dribble.

Exum was still going to be a minus on offense this season, but if he would have been a bit less of one, the Jazz could have really been onto something. They also lose a year of Exum learning through mistakes, meaning he’ll be less prepared to shine in 2016-17 — when Utah might really be ready to take off.

Utah had chances to upgrade at point guard, their quickest way to skip steps up the Western Conference ladder. As I wrote in April, they were open to trading their first-round pick for an upgrade at point guard, but could not find a match. George Hill may have been the most realistic option, but it’s unclear if the Jazz and Pacers ever seriously discussed such a deal, and they don’t appear likely to rekindle those talks now that the draft has passed.

With about $6.7 million in cap room, the Jazz could open up more by waiving a couple of the four nonguaranteed deals they’re carrying. They could absorb Jose Calderon in a salary dump from the Knicks, throw some cash at Norris Cole (presumably alive, hanging with Tristan Thompson), or take a point guard from a team seeking tax relief — Mario Chalmers from the Heat or D.J. Augustin from Oklahoma City. The Bucks don’t have enough minutes for Jorge Gutierrez, Tyler Ennis, and Jerryd Bayless (a hybrid guard) behind Michael Carter-Williams and Greivis Vasquez.

Bottom line: Utah is not doing anything rash for a stop-gap, at least not for now. It’s not giving up a pick for a marginal upgrade or taking on a midsize salary that runs beyond this season, like Calderon’s. The Jazz got this far being patient. Expect them to remain so.

We should also expect the usual flare-up about the risk of NBA players suiting up for their national teams in the offseason. After Paul George’s gruesome leg injury last August, Adam Silver said NBA owners and team higher-ups on the league’s competition committee would debate the merits of players participating in FIBA events. That discussion is ongoing, according to league sources, with a focus on both insurance coverage and the general rules for player participation in FIBA tournaments.

It’s unclear what could really change, or whether anything needs to. Teams have some authority to block their players from joining their national teams in the summer. If a team determines that a player is injured, or at risk for injury, it can hold him out; the Spurs did this with Manu Ginobili last summer, and sources say the threshold that teams must meet to prove their case is already pretty low.

The only foolproof way to prevent offseason injuries is to ban players from playing basketball, and that’s an uncomfortable path. Players want to play, and teams want players to improve over the summer. If they’re not playing in some FIBA event, guys will hit the Drew League, the Clippers’ open gym sessions in L.A., or the five-on-five action that breaks out at Impact Basketball in Las Vegas. They could just as easily turn their ankle the wrong way in any of those settings.

It’s plausible that international basketball takes more out of a player — the travel, the amped-up competition and pressure, the win-at-all-costs frenzy that gets players flying around in ways they never would during pick-up games. But lots of players enjoy playing for their national teams, they get better because of it, and the idea of removing the option brings the NBA closer to Big Brother territory. The NBA would have to collectively bargain any such changes with the union, and the players would justifiably fight back against any more restriction on their offseason activities.

To their credit, the loudest critics of the FIBA arrangement, including Mark Cuban, have been transparent about their goals: They are concerned with money, not player safety. They get that players are going to risk injury playing in big international tournaments; they just want the NBA, and by extension the players, to get their share of the revenue those tournaments generate. This is why David Stern kicked around the notion of turning the Olympics into an under-23 event and shifting all the biggest stars into a World Cup that FIBA and the NBA would run, and profit from, together. It certainly wasn’t about altruism or player health.

Bottom line is that one way or the other, players are going to play over the summer, and some of them are going to get injured. Within reason, the choice of whether and where to play should be theirs.