Baseball’s second half begins Friday, and with that come a number of intriguing storylines. Pennant races are in full swing, the trade market is heating up before the deadline, and teams look to make one final push to get them through the dog days of summer and into the fall.

It all comes down to the players, of course. Sure, baseball is a team sport, but often times, one player’s performance (or lack of) can swing a team’s entire season. With that in mind, here are 10 players who will have a big impact on the pennant races through the rest of the 2016 MLB season:

Clayton Kershaw, Los Angeles Dodgers

If the Dodgers are going to make a run at the Giants for the division crown, they’ll need Kershaw back to his healthy, dominant self. Back injuries are tricky, especially for a pitcher, and sometimes can take a lot longer than expected to heal. If Kershaw’s return gets pushed back, or if he comes back and re-injures himself, the Dodgers are going to be in trouble. With Kershaw, their rotation might be good enough to get them into the playoffs. Of all the players on this list, Kershaw is the one who means the most to his team’s chances.

Hunter Pence, San Francisco Giants

The Giants’ offense has done enough to make them the best team in baseball in the first half. But if it wasn’t for their stellar starting pitching, they’d likely be in the middle of the pack. That’s why Pence’s return is so important: just in case the pitching hits a speed bump, the Giants will need their offense to pick up the slack. Pence is scheduled to start a rehab assignment soon and could rejoin the team by the end of the month. That would be much faster than originally anticipated and if he’s healthy and playing at his normal level, the Giants should cruise into October.

Jay Bruce, Cincinnati Reds (for now)

Where will he end up? It doesn’t make much sense for the rebuilding Reds to keep Bruce around, so he’ll likely be on the move sometime before the first of August. You can make the case for just about any of the contending teams to add him. He’ll be the biggest bat on the market, one that can be a real difference-maker for a team in need of an offensive upgrade. A playoff race will likely be impacted by which team acquires him.

Andrew Miller, New York Yankees (for now)

If Bruce is the biggest bat on the market, Miller could be the best reliever available as the trade deadline gets closer. A lot will depend on whether or not the Yankees feel they’re out of the race. But if they do make Miller available, the price will be astronomical. But Miller might be the rare reliever worth the high prospect cost, considering he has the ability to shorten the game by at least an inning. He could swing a pennant race in favor of whichever team trades for him.

SAN DIEGO, CA - JUNE 3: Drew Pomeranz #13 of the San Diego Padres pitches during the first inning of a baseball game against the Colorado Rockies at PETCO Park on June 3, 2016 in San Diego, California. (Photo by Denis Poroy/Getty Images)
SAN DIEGO, CA – JUNE 3: Drew Pomeranz #13 of the San Diego Padres pitches during the first inning of a baseball game against the Colorado Rockies at PETCO Park on June 3, 2016 in San Diego, California. (Photo by Denis Poroy/Getty Images)

Drew Pomeranz, Boston Red Sox

Potentially the biggest name on the trade market for starting pitching, Pomeranz was dealt to the Red Sox Thursday for top pitching prospect Anderson Espinoza. Boston was in need of another rotation piece to take some of the pressure off of Steven Wright and the struggling David Price, and Pomeranz is in the middle of a career season. Still, he’s never thrown this many innings in one year (currently at 102) and there are still questions about how good he is. Has he turned the corner and turned into the pitcher everyone thought he’d become when he was picked fifth overall in 2010? Or was he a first half fluke waiting to be exposed in the powerful AL East?

Dee Gordon, Miami Marlins

The Marlins are chasing a playoff spot, and getting back their speedy second baseman should go a long way in getting them there. But what kind of player will Gordon be once he returns from suspension? It should be fascinating to see how he performs. The Marlins will try to squeeze whatever they can from him for a few months and hope he can push them to at least a Wild Card berth (which he wouldn’t be eligible to play in, by the way) and then deal with the fact that they still owe Gordon a ton of money over the next half-decade. That should be fun to watch.

Dallas Keuchel, Houston Astros

The Rangers don’t look so invincible anymore and the Astros are right on their heels in the AL West. To catch up fully, though, Houston will need a lot more from their ace than what they got in the first half. Keuchel has looked like his old self in his first two July starts so perhaps he’s regained his Cy Young Award-winning form. The Astros sure hope so, because they have little chance of making it back to the postseason without Keuchel performing at an elite level.

Corey Kluber, Cleveland Indians

The Indians look like the best team in the American League, thanks in large part to their pitching. But their former Cy Young winner has had an up-and-down season at best. There are times when he looks absolutely unhittable, and times when he’s liable to give up six earned runs in less than five innings. If Kluber can somehow lock in and pitch to the level he’s capable of, the Tribe’s rotation will go from great to elite in the second half. So will their chances of winning the pennant.

jake arrieta

Jake Arrieta, Chicago Cubs

Are the innings catching up with him? Over his last three starts in the first half, Arrieta gave up 15 earned runs (or the amount of earned runs he’d given up in his previous nine starts combined) and saw his ERA jump up almost a full run. He certainly hasn’t looked like the unhittable machine he’s been over the past year and a half and with his struggles, the Cubs themselves have fallen from their perch at the top of the National League. His first few starts in the second half should be fascinating to watch, because if he continues to struggle the Cubs’ dream season might go down with him.

Bryce Harper, Washington Nationals

The reigning NL MVP struggled some in the first half of the year, though a lot of hitters would gladly take his “struggles” if it meant an .891 OPS. Still, Harper hasn’t yet hit his stride this season and the Nationals are in first place. If he does hit his stride, the Nats could lock up the division early, get rest for their key players, and maybe even lock up home field advantage for the NL playoffs. Plus, it should be fun to watch him make a push for a second MVP award.

About Dave Tobener

Dave Tobener has been writing about baseball for the better part of a decade. He's been to more Giants games than he can remember and was there when Ruben Rivera forgot how to run the bases. Follow him on Twitter: @gggiants