Second-half X-factors: Which players could swing MLB season?

As MLB enters the second half, which players could have the biggest impact on their teams' playoff chances? Albert Chen looks at seven who could be major X-factors.

Welcome, folks, to MLB’s second half, where we will find out if it is indeed the Year of the Cubs; if even-year baseball prophecies are no more reliable than visions from red priestesses; and if home runs are truly back in a big way (though whether the homer spike is due to a juiced ball, global warming or Brexit will remain anyone’s guess).

It should be another dramatic second half, with all but 10 teams within six games of a playoff spot and the Chicago media already pouncing on panic narratives. As the curtain rises for Act II, we’re here to identify the biggest X-factors in each division—the players who help will shape the storylines everywhere from Believeland to La-La Land.

AL East: Aaron Sanchez, Blue Jays

In recent years, major league clubs have handled young pitchers like rare blue diamonds, as in the cases of Stephen Strasburg, Matt Harvey, Julio Urias and so on. But because no two arms are alike—because every pitcher has his own unique history—the reality is that when it comes to innings limits and workload decisions, it's all pretty much a guessing game.

Which brings us to the case of Sanchez, who was a first time All-Star in San Diego and was the best starter on the Blue Jays in the first half. Sanchez forced his way into the rotation during spring training, though to anyone who has followed him, his breakout has not been a shock: He has been long regarded by evaluators as a potential top-of-the rotation arm, and this spring, he looked not only like Toronto’s best pitcher but also like someone who had the potential to be one of the best starters in the AL, which he has been (his 2.97 ERA ranks fourth in the league).

• Red Sox prioritize present in trade for Padres' Pomeranz

But now what will the Blue Jays do with their 24-year-old righthander? He has never thrown more than 133 1/3 innings in a season; at the All-Star break, Sanchez was already at 118 1/3, which ranks 10th in the majors. If Toronto moves Sanchez to the bullpen, it loses its best starter. At the same time, the move would strength a relief unit that has been a weakness. Then again, it's no guarantee that a young pitcher making that transition midseason is going to thrive.

For now, the Blue Jays will closely monitor Sanchez’s next few starts and go from there. They're in the thick of a white-knuckle race—the Jays and Red Sox are within two games of the AL East-leading Orioles—and how they handle Sanchez will go a long way in determining whether they get another crack at their first championship since 1993.

AL Central: Michael Brantley, Indians

It’s not quite slaying-the-Warriors impressive, but what Cleveland's baseball club has done this summer has been impressive nonetheless, steamrolling the competition—the Indians have a 6 1/2-game lead in the division and possess the best run differential in the league—despite an offense that’s been hurt by the absence of the injured Brantley; putrid production from the catcher tandem of Yan Gomes and Chris Gimenez; and the loss of outfielder Marlon Byrd to a PED suspension.

The Indians are pitching-stacked, and the rotation could be even better with more starts from Carlos Carrasco, who was out for a month, and an even more dominant second half from Corey Kluber (his 2.95 FIP leads the AL). But Cleveland could also be making its version of a splashy deadline acquisition to help the offense if Brantley returns, as expected, and can perform up to his standards. Yes, we’ve been here before: Brantley returned from a shoulder injury in April, only to land back on the DL a few weeks later. Brantley recently began his second rehab assignment of the season, at Class A Mahoning Valley, and this time around, neither he nor the Indians are holding back their enthusiasm. “I know how my body feels. I’m in a great position," he told Cleveland reporters before the All-Star break.

Those words are one big reason why the party in Cleveland could keep raging into autumn.

• Making bold second half predictions for American League

AL West: Alex Bregman, Astros

They keep coming, these young Astros studs, from shortstop Carlos Correa to starter Lance McCullers to first baseman A.J. Reed to the newest shiny thing, Bregman, who finished a home run shy of a cycle in this year's Futures Game and could be called up to Houston any day now. A shortstop and the No. 2 pick in the 2015 draft, Bregman hit .297 with a .415 on-base percentage, 14 homers and 46 RBIs in 62 games for the Double A Corpus Christi Hooks, and with Correa blocking him at short, he figures to move to third base, shifting Luis Valbuena over to first.

The Astros were the big story of last season, faded in October and were left for dead after stumbling out of the gate this season. Now they’re suddenly just 5 1/2 games behind the Rangers in AL West. If Dallas Keuchel rediscovers his Cy Young form and ignites the underachieving rotation, and if Bregman adds firepower to an offense that’s beginning to fire on all cylinders, those lofty preseason predictions might just be realized.

• Verducci: Forecasting second half for Cubs, Mets, Yankees and others

Mark J. Terrill/AP

NL East: Dee Gordon, Marlins

Don’t sleep on the Fish: The Marlins, tied for second with the Mets in the NL East and six games behind the Nats, are the lurking breakout team of 2016. They’ve done it with a starting rotation that beyond Jose Fernandez has largely been a flop (most notably, $80 million free-agent addition Wei-Yin Chen is having by far the worst season of his career); with Giancarlo Stanton’s baffling first-half struggles (hitting .233 and striking out more than a third of the time); and with Gordon, their leadoff hitter and the 2015 batting champ, having missed a chunk of the season due to a PED suspension.

Now, after two months on the sidelines, Gordon is due back by the end of the month, and while it’s stating the obvious to say the Marlins will be better with him, it’s unclear what precisely his role will be on the team. Gordon possesses game-changing speed and is coming off two-straight All-Star seasons, though in his absence, Derek Dietrich has been excellent, with a .303/.396/.442 slash line on the year. President of Baseball Operations Michael Hill told the Miami Herald that the Marlins will “be creative” with regard to using Gordon and Dietrich at second base, but Dietrich and even Gordon—who, remember, isn't postseason eligible as a result of his suspension—could be sneaky trade chips as Miami looks to bolster its starting rotation and position itself for a big late summer push.

• Bold predictions for how second half will shake out in National League

NL Central: Jameson Taillon, Pirates

It’s remarkable that the Pirates, just three games over .500 heading into the second half, are in the thick of the NL wild-card race given how bad their starting pitching has been. Entering this season, Pittsburgh brought in Jon Niese, Juan Nicasio and Ryan Vogelsong and turned them over to Ray Searage, the team’s pitching Midas, expecting gold, but this has been one of the few years the Pirates have failed to hit big on any of their off-season lottery tickets. To make matters worse, ace Gerrit Cole has been injured, and Francisco Liriano is having his worst season ever in black and gold. And yet the Pirates still have a shot at making their fourth straight postseason for the first time in franchise history.

Whether the Pirates can fend off the Cardinals, Mets, Marlins and Dodgers in the wild-card race—or even catch the Cubs in the NL Central, where they’re 7 1/2 games back—will clearly depend on their starting rotation, and the key may very well be Taillon. The former No. 2 pick who has missed two seasons with injury returned this year improved off of Tommy John surgery—more of a command-control pitcher who, at 24 years old, seems to have figured things out. On June 14, he took a no-hitter into the seventh and pitched eight shutout innings against the Mets, though he began experiencing shoulder fatigue soon after. Taillon should return to the rotation shortly, and fellow top prospect Tyler Glasnow, the 6'8" righthander Pirates fans have been clamoring for, should also figure to play a role. With these two young arms and the Pirates’ recent track record, you should be bullish on Pittsburgh overcoming a slumbering first half and making a run.

• The 30: New team takes over first place as first half comes to close

NL West: Hyun-jin Ryu and Brandon McCarthy, Dodgers

What to make of the Dodgers? On the one hand, they’re on pace for their fourth straight 90-win season, and if the playoffs began today, they’d be putting up the bunting at Dodger Stadium for the wild-card game. On the other hand, they’re 6 1/2 games out of first in the division and, as the best team that $227 million can buy, feel like a big-budget Hollywood bust. The pitching staff has been hardest to figure: Alex Wood has been out since late May, Scott Kazmir has been inconsistent, Brett Anderson won’t be back until mid-August at the earliest, Julio Urias will be on a tight innings cap, and Clayton Kershaw is on the DL.

But there is reason for hope. Kershaw should be back soon, and McCarthy and Ryu—the reliable arms that the Dodgers have sorely missed—returned just before the All-Star break. Their return to the starting five should take some of the pressure on a quick recovery and return from Wood and Anderson. McCarthy and Ryu, of course, need to perform, but their track records suggest they could be big difference makers if they’re healthy. They’re the difference between the rotation looking like a flop, or like one that could make some serious noise in October.