Buckle in for what should one of Major League Baseball’s most volatile seasons, competition-wise, in recent memory.

With recent trades and free-agent signings fortifying back-end clubs in the National League West, at least two dozen clubs can count themselves as playoff hopefuls, whether they’ve expended hundreds of millions to more than a billion dollars at the cause, or not.

And certain players will profoundly impact those outcomes – by their performance or even their sheer availability.

With the assumption that stars will be stars, the dozen spots available to the 2024 postseason will hinge on swing players overperforming or succumbing. USA TODAY Sports takes a look at five of them:

Jung Hoo Lee, Giants

It’s been a bizarro decade in San Francisco, the baseball world rapidly changing since the Giants captured the last of their three World Series championships. Since then, the club ushered out the architects of that dynasty, brought in a “modern leadership structure,” alienated fans, had the greatest single season in franchise history, dropped out of contention yet again and then could not give their money away to elite free agents.

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But Jung Hoo Lee said yes. And now the club’s $113 million man only needs to provide production from the leadoff spot, an above-average glove in center field and charisma to woo a fan base alienated by years of platoon-mad nondescript baseball.

No pressure, man.

That was ratcheted up when the Giants tripled down on their free agent foray, GM Farhan Zaidi waiting for the market to creep downward before snagging third baseman Matt Chapman and reigning National League Cy Young Award winner Blake Snell.

Chapman and Snell are known commodities with well-chronicled drawbacks. They will very likely perform commensurate with expectations.

Lee, though, is hopping from South Korea’s KBO to the majors at 25. Giants fans would be thrilled if his high-water 2022 season was anything close to his normal – a .318/.406/.455 slash line with 23 homers.

For now, he is a great unknown – and how he fares will significantly impact whether the Giants are again a .500-ish team or can ease ahead of the division rival Padres and Diamondbacks into firm playoff contention.

DJ LeMahieu, Yankees

No doubt, Gerrit Cole’s elbow injury that will sideline him until at least June threw a major crimp into the Yankees’ plans. But their hopes of fielding a dominant squad aren’t dead. They’ll just have to do so in a different manner.

Namely, by pummeling opponents.

With no reliable ace to front the rotation, the Yankees can lean into a lineup that runs six deep with All-Stars and features a generational slugger in his prime nestled just one slot in the lineup behind a guy who hit an American League-record 62 home runs just two years ago.

But this potential machine can’t run on Juan Soto and Aaron Judge alone. Enter DJ LeMahieu.

At 35, he’s years removed from making history as a batting champ in both leagues or banging out more than 50 extra-base hits or reaching base at a .400 clip. The Yankees would love that guy to show up, but they don’t necessarily need that guy to show up.

Instead, a healthy and reliable LeMahieu atop the order might make the Yankee lineup almost unnavigable.

With Anthony Rizzo looking spry again after an undiagnosed concussion ruined his 2023, and Gleyber Torres coming off a bounce-back year and entering a platform season to free agency, the Yankees from 2-6 are again imposing.

LeMahieu, then, simply needs to stay healthy and productive to set the table for those guys. He was dogged by toe injuries last season, when his OBP tumbled to a career-worst .327.

Alas, DJLM will also start this season on the injured list, after fouling a ball off his foot a week ago and suffering a bone bruise. Unlike Cole, however, LeMahieu should return soon. The Yankees can scarcely afford him to be anything but healthy and productive going forward.

Frankie Montas, Reds

There’s a lot to like about the Reds, starting with opportunity: The NL Central is eminently winnable, and this Cincinnati lineup is the type that would be a postseason pain, with excellent on-base ability, speed and power.

Now, to get there.

They’ll need pitching to do that, and Montas will throw the first pitch of their 2024 season Thursday, a storied assignment in Cincy. It’s a big deal for Montas after injuries sidelined him for all but one outing in 2023, and bigger still for the Reds.

In short, can Montas return to anything approaching his 207-strikeout form of 2021, and let a young and developing rotation settle in behind him?

Importing a veteran often has a nice downstream effect, and in Cincinnati, it allows former No. 1 overall pick Hunter Greene a chance to recalibrate rather than reach outsize expectations, for second-year man Andrew Abbott and veterans Graham Ashcraft and Nick Martinez ease into substantial roles.

Montas, still just 31, led the AL by making 32 starts in 2021, throwing 187 innings. If he gets anywhere near that number for the Reds, it’s probably a very good season in the Queen City.

Josh Lowe, Rays

It’s easy to see the Rays as a pitching lab complemented by a bits-and-pieces offensive amalgam that leans heavily on platoons.

Yet at their best, the Rays have had star power in their lineups, from Evan Longoria back in the day to Randy Arozarena, Wander Franco and Yandy Diaz in recent years.

With Franco’s career in doubt, however, and Diaz and Arozarena approaching or exceeding 30, it would help to reestablish a burgeoning young All-Star.

Even better if that guy was Josh Lowe.

Just 26, Lowe hinted at his all-around talent a year ago when he paired 20 homers with 32 stolen bases and a .835 OPS in 135 games. Since then, both sectors of the Rays have taken a hit.

Franco, an All-Star a year ago, remains in legal limbo in the Dominican Republic and also faces the specter of discipline from Major League Baseball. And the dominant pitching staff that helped Tampa Bay to a 27-6 start that paved the way to a 99-win season remains strafed with injuries, with tentative hopes for midseason comebacks.

The Rays are in a sort of limbo, with projected win totals in the mid-80s, which in the AL East may only be good for third or fourth place. Lowe, too, is in a holding pattern, sidelined with an oblique strain that will keep him off the Opening Day roster.

Yet the best version of these Rays is Lowe’s left-handed bat tucked between Arozarena and Diaz or Harold Ramirez, providing power and speed and on-base acumen. The Rays will be good again. Lowe ascending to All-Star status might make them great.

Wyatt Langford, Rangers

We’re going on a quarter-century without a repeat World Series champion. There’s no shortage of reasons why, and now the expanded playoffs have made a menacing formula even harder to crack.

But it never hurts to change up the mix rather than run it back with an identical crew expecting the same outcome. Especially when that addition is the most exciting power prospect in the game.

Langford has made the Texas Rangers’ roster, just nine months after he was still competing for Florida in the College World Series. He will bat in the middle of the lineup, facing Chicago Cubs left-hander Justin Steele after exactly 200 professional plate appearances.

He hit 10 home runs at four minor league stops, with an 1.157 OPS. Small sample size? Sure.

The collegiate one is a little larger: Forty-seven home runs in 610 plate appearances across three seasons. Hey, it’s always wise to exercise caution about prospects, to temper the excitement.

But this is a fascinating match, prodigious power joining reigning champs. The Rangers enter the year wobbling a bit already. MVP runner-up Corey Seager will answer the Opening Day bell after sports hernia surgery, but with just one exhibition game under his belt.

Pitchers Max Scherzer, Jacob deGrom and Tyler Mahle are all on the shelf, recovering from myriad surgeries. The team played 179 games last season; a hangover year might be partially expected.

Langford represents that shot of adrenaline to get the system moving again. And the Rangers might really need it.