Can Julio Cesar Chavez Jr. still compete at an elite level?

Throughout his unlikely run to the outskirts of boxing’s elite in recent years, Julio Cesar Chavez Jr. has an uncanny knack for summoning competing emotions from those who watch him fight.

He’s part clown prince and part spoiled brat -- the son of a Mexican legend who is so defiantly unmoved by the constant disrespect he shows to the sport. Yet he’s also a comedic genius, able to play the role of villain so convincingly due to the crazy eyes and evil grin he flashes while talking trash.

Inside the ring, the former middleweight titlist has steadily floated between labels of overrated and underrated due to his polarizing nature and the inconsistency of his performances.

Yet through it all, Chavez leaves you cheering for him to lose just as much as you cheer for him to remain relevant. And it’s the latter that JCC Jr. could soon have an issue with if he doesn’t get the train back on the tracks.

Chavez (48-2-1, 32 KOs) faces unheralded Marcos Reyes on Saturday (Showtime, 10 p.m. ET) at the Don Haskins Convention Center in El Paso, Texas. The 10-round super middleweight bout marks a quick turnaround for Chavez, who suffered the first knockdown and stoppage loss of his career in April against Andrzej Fonfara.

The defeat was an unmitigated disaster for Chavez, who agreed to face the light heavyweight contender at a catchweight of 172 pounds. Not only was it Chavez’s first fight in more than a year, it proved to be a one-off with respected trainer Joe Goossen, who was jettisoned after the bout in favor of Robert Garcia.

Chavez, who went against the advice of his father by choosing Fonfara, simply couldn’t overcome the size difference as Fonfara systematically broke him down before Chavez quit on his stool after Round 9.

Whatever Chavez had previously lacked in terms of talent or work ethic, he had compensated for by leaning on his toughness and size. Against Fonfara he was delinquent in both, with Chavez’s postfight excuses regarding the size deficit he faced proving ironic due to how much his run as a middleweight was reliant upon the same exact thing.

Chavez’s dramatic weight cuts to 160 pounds once allowed him to rehydrate upward of 20 pounds. His exploitation of the day-before weigh-ins mixed perfectly with his chin and relentless body attack to make him a unique threat in the division.

While Chavez’s middleweight title run was aided by his last name and connections to the WBC, he could also fight and showed tremendous advancement under then-trainer Freddie Roach, who added a few wrinkles of craft to Chavez’s plodding style.

But Chavez the titlist ultimately couldn’t overcome the pressure of his toughest opponent: himself. He failed to adequately train for what became a one-sided beatdown against middleweight champion Sergio Martinez in 2012, even though a 12th-round knockdown helped him partially save face.

The next two and a half years were mostly wasted for Chavez, who endured drug suspensions, lengthy hiatuses from the ring and a pair of bouts against the much smaller Bryan Vera, including one in which an uninspired Chavez clearly benefited from a gift decision.

It all led back to April and his comeback against Fonfara. This was the fight against a legitimately tough opponent created to remove all remaining doubt about whether his career was truly anything more than a traveling circus. But despite taking camp seriously and coming into the fight in shape, the joke was on Chavez.

By all accounts, fatherhood has mellowed him, making Chavez less of a threat to himself in terms of his dedication. But the jury is still out regarding whether he can dial back and be that aggressive force of old.

Can Chavez, 29, still compete at or near an elite level when size is not an overwhelming advantage at super middleweight? Can his brand survive both his own self-destructive transgressions and the memory fans have of his “No mas” moment against Fonfara?

Just how well he meshes with new trainer Garcia, one of the sport’s very best, will go a long way in answering the major questions as Chavez prepares for what amounts to his final shot at finding out how good he can be.

His last stand begins on Saturday against Reyes, when anything short of a dominant win would be another disaster -- the kind of which Chavez no longer has the luxury of affording.