To say that rookies have had an impact on the 2015 season would be an understatement. Across MLB, teams have turned to untested players, and reaped massive rewards. The Nationals are just the latest franchise to call up reinforcements from the minor leagues to help boost their chances of success. As August comes to a close, and the final stretch run for the playoffs gears up, there are a handful of teams that will rely on their rookie presence to push them into October, and hopefully bring home a championship.
The Chicago Cubs
Out of all the teams in baseball, the Cubs are perhaps the most indebted to their rookie class. The story at the beginning of the season was where über prospect Kris Bryant was going to wind up, AAA or the majors, and to the chagrin of almost every Cubs fan, he began the 2015 season in the minors. However that didn't last very long, and Bryant has now accrued 475 plate appearances, and posted a slash line of .258/.364/.458. He also owns an ISO of .200, a wOBA of .358, a wRC+ of 128, and an excellent fWAR of 4.2. He's been without question one of the main factors behind Chicago's ascension to legitimate playoff contender; but he hasn't been the only rookie to help out.
The Cubs also owe a lot of their success to Addison Russell, and Kyle Schwarber. Russell was acquired in the trade that sent Jeff Samardzija and Jason Hammel to Oakland, in what many executives and baseball experts considered to be a steal. According to Peter Gammons, when the trade was completed, Billy Beane told Theo Epstein that he'd gotten the second coming of Barry Larkin.
While he hasn't yet fulfilled that promise, it's easy to see why Russell has drawn comparisons to players of that ilk. According to FanGraphs, his raw power grades out at a 60, while his future value is a touch higher at 65. He's been fantastically valuable defensively, and he seems to be hitting better now that he's made some mechanical adjustments at the plate.
Schwarber is the other Cubs über prospect, and while he was the last of this trio to be called up, he's proving to be the best of the three. In 144 plate appearances, he's slashed .303/.403/.598 with an ISO of .295, a wOBA of .424, and a wRC+ of 174. He's already accumulated 1.6 fWAR, which adjusted for Bryant's PA's, would translate to roughly 5.2 fWAR.
These three players, combined with Anthony Rizzo, Dexter Fowler, and a surprisingly valuable Chris Coghlan, have helped give the Cubs one of the deepest lineups in the National League, and could propel them to their first playoff berth since 2008.
The Minnesota Twins
While the Twins keep fading in in the Wild Card race, one of their rookies keeps on hitting, and doing everything he can to help them reach the one game playoff. Miguel Sano was called up in early July, and since then has hit .284/.394/.567 with a wOBA of .409, and a wRC+ of 165. He's flashed enormous power, as his ISO of .284 reflects, and has quickly become the Twins most feared hitter. His raw power grades out at and 80, the highest rating possible, and he figures to be a part of their lineup for years to come.
Byron Buxton unfortunately hasn't yet proven himself at the big league level, but according to MLBPipeline, he's the Twins best overall prospect, and with time, he should begin to put together prolonged success. He possesses blazing speed, and should become an excellent defensive player in time.
The Houston Astros
The Cubs undoubtedly have the best group of prospects, but the Astros might have the most valuable individual player. Carlos Correa is just 20 years old, soon to be 21, and has already been worth roughly three wins according to fWAR. He's hit 15 home runs in just 273 at-bats, which puts him four back of the MLB leader for shortstops. He's drawn comparisons to Alex Rodriguez, and has eclipsed several all-stars in terms of production for his first 62 games.
Carlos Correa is off to an AMAZING start to his career. #WhipAround pic.twitter.com/9KEUOV3M4N
— FOX Sports: MLB (@MLBONFOX) August 20, 2015
The San Francisco Giants and Los Angeles Dodgers
The top two teams in the NL West have each relied on rookies this season, but for the Dodgers, Joc Pederson might not be enough. He started off incredibly hot, and not only looked like one of the front runners for the Rookie of the Year award, but also that he might get some votes for the MVP. However, since the All-Star break, Pederson has hit .169/.336/.303, with a wRC+ of 89, and a meager ISO of .135. His power has seemingly disappeared, which is likely one of the reasons that the Dodgers felt compelled to acquire Chase Utley.
The Giants' rookie however, Matt Duffy, has not faltered down the stretch run, and in fact has gotten better. In his last 142 PA's, Duffy has posted a slash line of .326/.352/.459, a wOBA of .351 and a wRC+ of 131. He's produced an fWAR of 3.7 through 108 games this season, and been incredibly valuable to a team that was planning on letting Casey McGehee play on an everyday basis.
These rookies are just a few of the many that have been brought up this season. Randal Grichuk has been another fantastic addition to an already strong Cardinals team, and could be a contender for the NL ROY should he return from his elbow injury in good health. Rookies represent an incredible commodity, as they can provide a lot of value for almost no cost at all; and with their contributions in 2015, their overall stock has likely risen.