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Tony Parker has continued to slash through defenses during his 14th professional season for the San Antonio Spurs, maintaining his status as the driving force of Gregg Popovich's offense.

Contrary to what Tim Duncan's career may suggest, however, Parker won't last forever. Kawhi Leonard is the superstar heir apparent, but San Antonio must address the eventual void Parker will leave.

Though that situation is certainly not an immediate worry, franchise point guards don't grow on trees—or draft boards. And neither does Cory Joseph.

"He comes in and he makes it tougher for the other team to score. He gets loose balls. He rebounds," Popovich said, per Jeff Caplan of Fox Sports Southwest. "He does everything that helps the team, all the blue-collar kinds of things. But hardly anyone notices it."

A first-round draft pick in 2011, Joseph immediately joined the end of the Spurs' bench. The University of Texas product logged 654 minutes throughout his first two seasons, appearing in 57 games.

Ultimately, Joseph's most memorable headlines came when he asked Popovich, according to Ken Rodriguez of Spurs.com, "Can I go back to the D-League?" Joseph hadn't played much in the big league, so he wanted to improve in the way he knew best.

The move slowly endeared himself to San Antonio fans, and more importantly, it's paid off for the 2013 D-League All-Star at the premier level. Joseph was a key rotation player last season, registering an average of 13.8 minutes over 68 showings.

This year—the final season of his rookie contract, per HoopsHype—however, is when the 6'3" guard's desire to develop as a young pro has become increasingly important. When Parker and Patty Mills were sidelined due to hamstring and shoulder injuries, respectively, Joseph stepped into his largest role yet.

From Dec. 6 to Jan. 3—a brutal 16-game stretch against 11 playoff-caliber teams—Joseph tallied 33.3 minutes, 12.8 points, 4.0 rebounds, 3.6 assists, 1.0 steals and just 1.6 turnovers per appearance.

That success consequently propelled him into trade discussions, since Joseph could be added if the Spurs were to engineer a deal. San Antonio likely doesn't have many pieces with which the front office is willing to part, after all.

He's a movable asset, but Joseph's consistent, outstanding play has made the execution of that option more difficult.

Mills and Joseph have been dueling for playing time behind Parker, but the reserve point guards bring vastly different skill sets to the equation. While the Australian is an energy-filled three-point specialist, Joseph initiates the type of offensive sets that lead to Mills' triples.

Plus, the impending departure of 37-year-old Manu Ginobili—perhaps as soon as this offseason—creates another question in the Spurs backcourt.

Joseph could continue developing into a shot-creator for the second unit. He's capable of finishing at the rim in traffic, something Mills will rarely, if ever, convert, let alone attempt.

The Spurs will undoubtedly miss Ginobili's ability to attack the pick-and-roll, and it's not easily replaceable. Nearly every guard will attempt to split a pair of defenders, but not many can accomplish it consistently.

Though Ginobili is often an adventurer in the paint, many NBA teams would love to have the Argentine for their bench. Similarly, the same franchises must be keeping an eye on Joseph, a restricted free agent.

While he's far from a polished offensive product, Joseph atones for that current shortcoming with superb efficiency, as noted by Jesse Blanchard of Indubitably Hoops.

Though Joseph still lacks gravity—the ability to bend defenses in his direction—his constant movement keeps his defender occupied and presents driving lanes that allow him to showcase his improved finishing ability. Though he still doesn't create enough passing lanes, he reads defenses well enough on the move to make dump off passes presented to him and avoid turnovers.

Joseph is only 23 years old, so he has approximately three more seasons before reaching what is considered an athlete's prime. In other words, Joseph has plenty of time to improve further under the guidance of a future Hall of Famer.

He's already progressed while replicating some of Parker's offensive arsenal. According to NBA.com, 65.3 percent of Parker's baskets have been unassisted, and Joseph has tallied a 55.4 percent mark. For reference, Ginobili has recorded a 41.4 percent clip.

The backup point guard leads the trio with a 59.5 percent mark within five feet, while Parker and Ginobili have accumulated 57.3 and 52.9 percent, respectively.

Joseph has also converted 16- to 24-foot jumpers at a higher rate than his teammates, burying 44.2 percent of his looks compared to Parker's 39.7 and Ginobili's stunning 12.5.

Overall, per Vorped, Joseph has knocked down 48.9 percent of his attempts outside the lane and inside the three-point arc, whereas Parker sits at 39.0 and Ginobili at 32.8.

Three-point shooting is a legitimate counter-argument, since Ginobili has attempted 4.1 per night and Parker has nailed 50.9 percent from downtown. Joseph has only hoisted 36 triples all season, yet his current 33.3 percent success rate is better than eight of Parker's 14 career campaigns.

None of those numbers are intended to argue Joseph is a superior player to his teammates or that he'll become a bona fide star like Parker or Ginobili. Rather, the point is Joseph's value to the Spurs is undeniable.

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San Antonio isn't going to ditch Parker in favor of a solid backup, and Ginobili will finish his career in the silver and black. Besides, both veterans were key elements to the Spurs' championship last year as Joseph largely watched from the bench.

Parker has encountered his share of struggles this season, but the franchise is still reliant on him for their repeat championship hopes. Ginobili's inconsistency can test Popovich's patience, but the sixth man is still a weapon.

Joseph's on-court performance in 2014-15 is likely to garner him an enticing offer this summer, and playing time will remain a premium in San Antonio if Ginobili returns. Consequently, the Spurs don't need to prioritize Joseph as the point guard of the future if the price isn't right.

However, San Antonio certainly could do worse than granting Joseph a couple more years to develop into a key complement for their soon-to-be superstar in Leonard.

Unless otherwise noted, stats are courtesy of Basketball-Reference.com and are accurate as of Feb. 9.

Follow Bleacher Report NBA writer David Kenyon on Twitter: @Kenyon19_BR.