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LOS ANGELES — There are constant reminders that 22-year-old Boston Red Sox third baseman Rafael Devers is young.

Acne scars dot his face. He likes wearing two gold chains and bright green Air Max 90s. Blond tips sometimes poke out of his baseball cap with a haircut that's a cousin of Odell Beckham Jr.'s locks. Even his youthful appearance, which sometimes makes him look like a middle-schooler who sneaked onto the field in full uniform, has led Red Sox fans on social media to dub him their "young son."

In fact, Devers—who just turned 22 on Wednesday—is the youngest player on either World Series roster.

So Saturday night, when Devers stepped up to the plate in the ninth inning with the game tied 4-4 and Brock Holt on second base representing the go-ahead run, all the Red Sox could hope for was that his age didn't show.

"You're hoping and praying like hell that he's not going to try to hit it nine miles out of Dodger Stadium," assistant hitting coach Andy Barkett said.

With a 2-0 count versus Los Angeles Dodgers reliever Dylan Floro, Devers drove an 86 mph changeup into center field for an RBI single, helping the Red Sox grasp a 5-4 lead. It was one they would not relinquish in a 9-6 victory in Game 4 en route to a 3-1 lead in the 2018 World Series.

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It was just the latest clutch moment for a player who had already entered the postseason record book with RBI in eight straight games, matching Lou Gehrig, Alex Rodriguez and Ryan Howard. He's building a historic October resume in just his second trip.

"It was a really important moment for our team and a really important moment in my career," Devers said in Spanish after the game. "It was an opportunity that I had, and I took advantage of it."

It was a moment months in the making, dating back to his stint on the disabled list with left shoulder discomfort amid a slump at the plate.

While Devers torched from the left side of the plate for most of the first half, hitting 14 homers and 20 doubles and knocking in 48 runners before the All-Star break, the league adjusted. He soon found himself slumping, hitting just .214 in July before joining the disabled list at the end of the month.

Suddenly, Devers found time to take a step back and breathe. He had time to make adjustments and re-evaluate his approach at the plate. It's a lesson every young player has to learn at some point: When the league adjusts to you, you need to adjust back.

"He hit a tailspin and started searching," Red Sox hitting coach Tim Hyers said. "He had the injury, wasn't in the lineup as much, and all of a sudden I saw him go to work and get into fundamentals. He went back to basics with his work. I saw him slow the game down and use the whole field."

Throughout the season, Devers and the Red Sox's coaching staff continued to build trust, a direct result of the clubhouse culture manager Alex Cora brought in at the beginning of the season.

When Devers saw his playing time diminish near the end of the season, Cora, Hyers and Barkett made sure to let him know he was still an integral part of the team, continuing to put him in positions to succeed through pinch-hitting opportunities and the occasional start.

It prepared him for a night like Game 4, when Cora decided to start Eduardo Nunez over him at third base. As the innings ticked on, Devers prepared himself to pinch-hit, to contribute whenever the team might need him.

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"I was ready for my moment to come, whenever that may be," Devers said. "Being in the National League, you've got to be ready from the first inning with obviously the pitchers hitting. So I just wanted to be ready for whatever the situation was."

With the righty Floro in the game, Cora and Barkett figured that Devers was the best matchup off the bench. Barkett went over the game plan, reminding him of the Dodgers reliever's weaknesses and what his plan should be when he stepped to the plate.

"Throughout this season, he's grown up a lot. Talking to him in April about game-planning was difficult," Barkett said. "Talking about game-planning in October is easy. He had a plan up there. He knew what the pitcher had. He did his work to prepare, and he was ready."

Devers' propensity to come up in the clutch has not gone unnoticed among the Red Sox. It's something that he has done consistently through this postseason run. In Game 5 against the Houston Astros, he hit a three-run homer that set up a 4-1 victory to clinch the American League pennant. In Game 4 Saturday, after his huge hit, his big-time throw on a grounder behind third base beat Manny Machado to first to stifle L.A.'s ninth-inning comeback rally.

In 10 games this postseason, Devers has nine RBI, and he has 14 RBI total in 14 career postseason games. After his heroics Saturday, he became the youngest player with a go-ahead RBI in the ninth inning or later since Edgar Renteria's walk-off single in Game 7 of the 1997 World Series, per ESPN Stats & Info.

In less than two full seasons in the big leagues, Devers has become one of the best hitters in high-leverage situations, hitting .300/.364/.400 this postseason alone.

"The kid is gifted," Barkett said. "He's got gifted eyes and gifted hands. He's strong, aggressive and powerful. That's what gives him the edge [in high-leverage situations]."

Without the slump, without three stints on the disabled list, without the time to slow things down and rededicate himself to fixing the fundamentals of his swing, the opportunity may have ended differently.

For many, the situation Devers found himself in may have been overwhelming. But when Barkett looked over at him, he saw a calm kid who wasn't looking to be a hero.

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"All we needed was a knock up the middle, and to his credit, on this stage, to be able to compose himself and get a line-drive base hit was pretty impressive," Barkett said.

Everything Devers went through this season, from slumps swinging at anything near the plate to changes he made after landing on the disabled list, led to his moment.

It ensured that instead of trying to hit a ball nine miles out of Dodger Stadium, he found his pitch and slammed one up the middle for the go-ahead run, setting up his team to win its ninth World Series title.

"I was grateful to have that opportunity," Devers said. "I was ready."