LOS ANGELES -- The first pitch Gavin Lux ever saw in the major leagues, a 93 mph fastball tailing low and away, he lined into shallow center field for a base hit. When he reached first base, the Los Angeles Dodgers broadcast panned to his mother, Heather, and his father, Tom, who had flown in from Kenosha, Wisconsin, to take in their son's debut on Labor Day. Tom, outfitted in a blue Dodgers T-shirt and cap, pumped both fists into the air, clapped his hands together a few times and turned increasingly more red through the process. His eyes began to swell. Tears started to become visible. The video made its way to Lux after the game.

"I thought he was the tough guy," Lux said behind a smile. "I thought he was gonna be the one to not do that."

Lux is here to stay now, through the month of September and potentially deep into October. He is the fifth highly rated prospect to play for the Dodgers in their dominant 2019 season, after Alex Verdugo, Will Smith, Tony Gonsolin and Dustin May. His ascent is the most unlikely, his immediate future the most enthralling.

Lux was on track to become the everyday second baseman by 2020, but the Dodgers could turn to him now, despite fielding the National League's greatest and deepest offense, to help capture the franchise's first World Series title in 31 years. It was a possibility dismissed by club officials as recently as four weeks ago.

"He earned his way here," Dodgers manager Dave Roberts said, "and he knocked the door down."

Lux, 21, overhauled his hitting mechanics in the summer of 2017 and overcame a mild case of the yips in the spring of 2019. He shot up the prospect rankings last year but attained mythical status after a recent promotion to Triple-A, tearing up the Pacific Coast League like few ever have. Lux batted .392/.478/.719 in the 232 plate appearances that preceded his major league call-up. He recorded 18 extra-base hits through his first 15 games and hit safely in 27 of his first 28.

Matt Beaty was drafted a year earlier and always played a level higher, but he kept hearing about Lux. When Beaty was sent back to Triple-A on July 10, he was curious to see him up close. Beaty spent three days with the team in Memphis, Tennessee, and saw Lux take 16 at-bats. He saw him line pitches all over the outfield and saw him launch a home run deep down the line on a humid night when balls weren't carrying. Seven of those at-bats ended in hits.

"He was locked in," Beaty said. "I've never seen a hitter that hot."

Lux will tell you it was all the result of "just going out there and being myself," which isn't fluff. The success of these past two years, which included a .336 batting average across four minor league levels, have been the culmination of Lux growing comfortable with new mechanics.

The Dodgers drafted Lux 20th overall out of high school in the summer of 2016 and in some ways remade him in the summer of 2017. Lux began that season in the Midwest League and didn't record his first extra-base hit until his 22nd game. Robert Van Scoyoc -- then a hitting consultant, now a hitting coach at the major league level -- flew in to help.

"It's a pretty difficult time of year to make changes," Van Scoyoc said, "but he was struggling to a degree that it was necessary."

The Dodgers reworked everything, from his hands to his swing to the way he sets up and the way he loads. They wanted Lux to have a strong foundation with his lower half and keep his bat through the strike zone as long as possible, with more loft in his finish. The changes would ideally give Lux better plate coverage and allow him to elevate pitches more easily, but implementing them became a struggle.

Lux finished that season with a .693 OPS, then spent the entire winter working to make the changes feel natural. The 2018 season began in the Cal League, and Lux recorded only nine hits through his first 43 at-bats. Most players, particularly young ones, would have reverted to their old ways.

"Luxy just kept with the process, trusted everything that he did over the offseason, and from that point on, he hasn't looked back," Dodgers assistant general manager Brandon Gomes said. "He's been one of [the best], if not the best, hitters in the minor leagues the last few years."

Gomes, who previously served as the team's director of player development, considers Lux an "ultimate professional." He raved about his mental toughness, his attention to detail, his desire to become great and his openness to new instruction. He said his makeup is "as good as it possibly can get."

For those reasons, Gomes said, he hardly worried when Lux seemingly forgot how to throw a baseball during spring training in Arizona.

Beaty, who spent a lot of that time as Lux's first baseman, knew there was a problem when Lux six-hopped a throw off a routine grounder at Camelback Ranch. Beaty exuded optimism. "Hey," he told Lux, "we got the out." But Lux wasn't easy to console. It was his first big league camp, before the most important season of his professional career, and he had the yips. It seeped into his mind and wouldn't leave.

The Dodgers encouraged Lux to set his feet before throwing and let the baseball go without fear. One day, in the back fields of the Dodgers' spring training complex, Jose Vizcaino, a major league infielder for 18 seasons, asked about his grip. Lux grabbed a baseball from his glove and placed his index finger and middle finger on the outer edges of it. Vizcaino, now a special assistant with the Dodgers, couldn't believe it. He advised him to keep his fingers close, the way most pitchers would throw a fastball, and saw the yips go away shortly thereafter.

"And look at the season that he's had," Vizcaino said. "If he was somebody else, who's not mentally strong, he wouldn't have the season that he's had."

Lux is still relatively new to second base, but evaluators believe it's his best position in part because the throw is shorter. Scouts now see Lux as an average-to-slightly-above-average defender. His bat, however, is elite at any level.

Lux's second-inning hit Monday was followed by a third-inning double in the right-center-field gap, which capped a six-pitch at-bat. His next three plate appearances ended in a fly ball to the warning track, a grounder to the right side and a popup to the infield, but they all lasted six pitches.

"That's who he is," May said. "If he's not hitting the first pitch, he's definitely going to take his time in the AB."

Lux jumped from eighth to first in the batting order Tuesday, a 1-for-4 showing in a 5-3 victory over the Colorado Rockies. He batted there only because Joc Pederson took the night off, and he is consistently in the lineup largely because Max Muncy is nursing a wrist injury.

The Dodgers have won 91 of their 141 games and can clinch a division title as early as Saturday, 22 days before the final day of the regular season -- but they still have a lot of loose ends.

Cody Bellinger is suddenly playing center field and A.J. Pollock is transitioning to left. Julio Urias is back from suspension and getting stretched out, joining May, Gonsolin and the recovering Rich Hill as options for the fourth spot in the rotation. Kenley Jansen is and isn't the closer, with Kenta Maeda suddenly an option to pitch in high-leverage situations, including the ninth inning. Verdugo will be back next week, but suddenly he has to earn his place in the lineup again.

And then there's Lux, who might blow this whole thing up.

"You're trying to find the best 12 to 13 position players to formulate your roster," Roberts said when asked about the possibility of Lux earning his way onto the roster, and perhaps becoming the starting second baseman, in the postseason. "To say that's impossible, that's not the case."