As baseball's second half begins, the problem with all this Trade Deadline chatter currently clogging up our brains and bandwidth is that many of the factors that will determine the division and playoff races are, in fact, internal ones.

Fates are riding not necessarily on some white knight riding in from the transaction wire but players already under team control. It could be an injured player due to return soon, a prospect who could be promoted or simply an underperforming player due (he hopes) for a second-half surge.

So with that in mind -- and because we simply don't know which players will be traded where -- here are a dozen players who rate as major second-half X-factors for contending clubs.

Noah Syndergaard, Mets

Well, yeah, if Jose Reyes can maintain that .708 slugging percentage he's sporting through six games, that would be pretty key for an erratic offense that was less-than-clutch in the first half.

But the Mets are ultimately a team built around that starting staff, and the starting staff has withered considerably in recent weeks. Steven Matz has an elbow spur that has limited his slider usage, Matt Harvey's done for the year, Zack Wheeler's return keeps getting pushed back and Jacob deGrom was so gassed by the break that he begged off an opportunity to be named to the All-Star squad.

Then there's Syndergaard, whose own elbow spur and arm fatigue were the source of great midseason hand-wringing among the Mets faithful. Against the backdrop of everything else going on in the rotation, to lose Syndergaard for a prolonged period or see him endure a significant stretch of poor performance would probably be a death blow in a season that already feels fragile. After a sudden drop in velocity that he likened to parachutes falling, Syndergaard is getting ample time off at the moment and won't make his next start until July 19. He plans to throw less between starts. He was adamant at the All-Star Game that this is a matter of fatigue, not pain, and Mets manager Terry Collins was adamant that the Mets are "not dead yet."

Their conditions run hand-in-hand -- or elbow-in-elbow, as it were.

David Price, Red Sox

Dave Dombrowski is, as expected, beating the bushes in search of pitching support, and he's already unearthed Brad Ziegler in an effort to patch up a 'pen reeling from the losses of Carson Smith and Craig Kimbrel. Those efforts will continue on in earnest, and Dombrowski has a deep system to work with. That system also includes Andrew Benintendi, who might be an outfield option in the second half for a Red Sox club that has looked for better left-field production.

But the bottom line in Boston is that it's really, really hard to imagine this club ending David Ortiz's career on a World Series-winning note if Price doesn't get back on track. The home run rate against Price has spiked considerably this season (15.2 percent of fly balls vs. 7.8 last year), and he's simply got to get that under control. But there's a large gap between his ERA (4.34) and Fielding Independent Pitching mark (3.42), which suggests that Price could be in line for a bounceback second half, and he might have demonstrated just that with an eight-inning gem against the Rays (no runs on four hits with a walk and 10 Ks) leading into the break.

Alex Bregman, Astros

Before the SiriusXM All-Star Futures Game on Sunday, MLB Network's Mark DeRosa asked Bregman what the world should know about him:

"That I'm ready."

The dude was then a homer shy of the cycle, like, minutes later, ripping a double, triple and single in his first three at-bats. He was one of the stars of that showcase of burgeoning stars, and this fell right in line with his performance at Double-A and Triple-A this year. You've got to give credit to Luis Valbuena for stepping up his offensive game as the Bregman chatter has built in recent weeks, but Bregman does figure to be up soon (even if reports of an arrival this weekend proved to be erroneous). Bregman could pull a 2012 Manny Machado with the full-time shift from short to third base, slotting into the two-hole and, perhaps, further igniting a surging Astros squad.

Jake Arrieta, Cubs

Dexter Fowler will be back very soon, and this club has sorely missed his presence atop the order. So he's an X-factor, but we can probably assume that he'll continue to produce. The bullpen is a major issue at the moment, and the Cubs will definitely go after and an arm or two.

But I'm going with Arrieta here because Joe Maddon has said many times that the reason the Cubs are THE CUBS this year is the pitching. And if what we saw from Arrieta basically in the second half of the first half continues in the second half (you still with me?), that's a big, big problem. Whether it's attributable to the effects of last year's 40-percent jump in innings or something more or less sinister, Arrieta has a 4.81 ERA going back to the beginning of June, and he was really roughed up in his last three starts before the break.

Arrieta was obviously instrumental in the Cubs' efforts in the second half last season, and with the potential for some overall statistical regression for this rotation group, the Cubs are going to need him to step up once again if they're going to get where they're expected to go.

Kevin Gausman, Orioles

I don't think it's indelicate to suggest that among all the current division leaders, the Orioles' situation certainly seems the most untenable. They've got a 5.15 ERA, for crying out loud. It's the third-highest mark in the Majors. And starters not named Chris Tillman (who probably should have been an All-Star) have a 5.70 mark.

So what happens if Tillman regresses from his current 130 ERA+ even slightly? Or what if that fabulous bullpen bends a bit? The O's offense is impressive, but that's a lot to overcome. This team needs not just a starting pitching upgrade (a tough thing to pull off in a thin market with a thin farm system) but starting pitching upside. Maybe Dylan Bundy impacts them in that area in the home stretch, maybe Mike Wright puts it together. But the guy who has enough starts under his belt and has shown enough flashes to suggest there is plenty more in the tank is Gausman. His adjusted ERA is just a bit better than league average, and there hasn't been a great deal of consistency to his outcomes.

The good news is that he's throwing his curveball more frequently (11.8 percent of the time vs. 9.7 last year) and getting substantially more swings and misses (12.3 percent vs. 6.6). As he continues to mature with that particular pitch, there's reason to believe this will be a more consistently effective arm for the O's moving forward. Honestly, for a team like the O's, there's more upside here than there is available to them in the trade market.

Marcus Stroman, Blue Jays

Aaron Sanchez has been awesome for the Blue Jays this year (2.97 ERA, 144 ERA+), but he's already exceeded his 2015 innings total. At some point -- perhaps soon -- the Jays are going to move him to a high-leverage relief role, so his second-half impact in the rotation won't be as strong as his impact in the first. Toronto needs Stroman, the undersized but upside-heavy right-hander who provided a late-season spark in his return from knee surgery last year, to balance things out.

Stroman has a lackluster line overall -- a 4.89 ERA and 1.33 WHIP through 18 starts. But there's plenty of hope here. In his last three starts before the break, the contact rate against Stroman went from 82.2 to 75.2 percent, and the swinging strike rate went from 8.1 percent to 12.5 percent.  

Reynaldo Lopez, Nationals

Lopez is a starter who pitched out of the 'pen in the Futures Game, and that might have been a preview. Because for a Nats team likely in need of a relief boost down the stretch this summer, his stuff, which includes a 100-mph fastball, is unbelievably enticing. The right-handed Lopez is striking out 11 batters per nine -- again, as a starter, so imagine what might happen if he just airs it out.

In that Sunday showcase, he retired the side (including Bregman) in order. Long-term, the goal remains to develop Lopez into a viable big-league starter, to improve the command of his curveball and changeup. But there are no rules in a World Series chase, and as the Nats try to seal the East, they could turn to Lopez to provide power out of their 'pen.

Jose Abreu, White Sox

Really have no idea what to make of the Sox after that roller coaster first half. James Shields appears to be settling in, and Tim Anderson has really changed the complexion of things atop the order. Justin Morneau, who is rehabbing from elbow surgery, could join this club around the beginning of August and, with his left-handed bat, could provide some of the balance this lineup sorely needs. So that's all good.

But look, it's really hard to take the Sox seriously as a legit postseason club if Abreu doesn't get it going with consistency. Though he did show signs of life late in the first half (he had 15 extra-base hits in the last 35 games after logging just 16 in the first 51), Abreu is nonetheless still currently saddled with by far the lowest OPS (.756) and adjusted OPS (105) marks of his young career. He's seeing significantly more breaking pitches than he did even a year ago (32.3 vs. 26.5), and Abreu's ongoing adjustment to that trend is an important issue for a Sox club that keeps making every effort to win now.

Clayton Kershaw, Dodgers

I'm not going to waste my time and yours by explaining why Kershaw is really, really good and important to the Dodgers. Pretty obvious that their fortunes might be directly tied to how many second-half starts he makes in the wake of the back issue that currently has him on the DL.

Michael Brantley, Indians

It has been one of the season's biggest injury sagas. The Indians announced Brantley's shoulder surgery in early November. And had you known then that Brantley would play just 11 games in the first half and that the organization's only external efforts to replace his production would be with the additions of Rajai Davis and Marlon Byrd (and that Byrd would be suspended for PED use), you would assume the Tribe was dead on arrival.

Quite the contrary. The Indians are 6 1/2 up in the AL Central and sixth in the AL in runs per game. Thanks to the improvement of Lonnie Chisenhall, the emergence of Jose Ramirez and Tyler Naquin and the strong output of Davis, the pending return of Brantley, who has begun a Minor League rehab assignment, currently feels more like icing on the cake as the Indians try to nail down their first division title since 2007. Whether Brantley can instantly impact Cleveland remains to be seen, because continuing issues with the lead shoulder sapped his strength in that brief initial return. But a cortisone shot and added rest and rehab has him feeling confident he can still provide production in 2016.

Yu Darvish, Rangers

The Rangers hit the ceremonial midway mark with the best record in the AL, and they did it with just three starts from Darvish. That's not something you would have expected going into the year, as Darvish's health and return from Tommy John was a pretty clear X-factor back in March.

Well, it still is a pretty clear X-factor, because this rotation, especially with Colby Lewis on the shelf, is going to have trouble maintaining what was an elite first-half performance when you look at its adjusted ERA. This rotation has the game's largest negative differential between its FIP and its ERA, so there's probably some regression in order -- and we might actually see that from Cole Hamels, who has strong 3.12 ERA currently despite a spike in homers allowed per nine.

Darvish went back on the shelf with shoulder discomfort after those three starts in which he was throwing harder than he had pre-surgery. Hopefully, for the Rangers' sake, he has a better feel for his mechanics and can get past this hiccup and get back to being one of the AL's best starting arms, because he's a bigger deal than any in-season trade Texas could make.

Andrew McCutchen, Pirates

The Buccos won nine of 11 going into the break, throwing cold water on the trade chatter that began to surround them and almost cutting their division deficit in half (it went from 14 games to 7.5). Maybe the Pirates don't have enough gas to catch up to the Cubs, but they can, at the very least, find familiar territory by winning yet another Wild Card and extending an impressive run of sustained success for a small market.

Of course, if the Pirates don't get more consistency and health from their rotation, which has already employed 11 men at various points, maybe none of what I'm about to say matters. But it's hard not to be concerned about what we've seen from Cutch this year. By a significant statistical margin, he's been the Pirates' third-best outfielder, which says a lot about the growth of Gregory Polanco and the continued excellent of Starling Marte but also, yes, a lot about McCutchen, too. He's striking out more (24.7 percent vs. 19.4 percent last year), walking less (8.8 vs. 14.3), not playing particularly good defense, not making much impact on the bases when he actually does get on base and even suffering from the occasional mental gaffe.

Just an odd year for the former MVP, but he's got a .314/.375/.543 slash so far in July, so maybe a second-half surge is in order.

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Anthony Castrovince is a Sports on Earth contributor, MLB.com columnist and MLB Network contributor. Follow him on Twitter @Castrovince.