Young sluggers and veteran additions have Cubs on the rise for 2015

Buoyed a bevy of top prospects, a new ace in Jon Lester and a proven winner in Joe Maddon at the helm, expect bigger and better from the Cubs this season.

This week, SI.com is previewing all 30 MLB teams, counting down to the No. 1 team in the league. At No. 16: the Chicago Cubs.

2014 Record and Finish: 73–89 (.451), fifth place in NL Central (23rd overall)

2015 Projected Record and Finish: 82–80 (.506), third place in NL Central (16th overall)

The Case For

The Cubs made waves this winter by plucking manager Joe Maddon away from the Rays, landing free agent starting pitcher Jon Lester via a six-year, $155 million deal and trading for pitch-framing wizardMiguel Montero to take over at catcher, a trio of moves designed to provide leadership for their up-and-coming core. While last year’s team finished below .500 for the fifth straight year—their third season under the Theo Epstein/Jed Hoyer regime—the second half of the season saw Chicago carve out time for an exciting wave of prospects who are integral to its future in Arismendy Alcantara, Javier Baez and Jorge Soler.

Sports Illustrated's 2015 MLB season preview rankings

That trio, whose results at the big league level were admittedly uneven, will enter their first full season alongside young-but-established Starlin Castro and Anthony Rizzo, both of whom were All-Stars last year, with slugging third baseman Kris Bryant, one of the game's top prospects, not far behind. If it all comes together, this could be the year that the rebuilding effort finally bears fruit, returning the Cubs to the postseason for the first time since 2008.

The Case Against

Chicago was a 73-win team last year, and the struggles of Alcantara (.205/.254/.367) and Baez (.169/.227/.324) serve to remind that not every prospect takes to the big leagues immediately, all of which makes the debate about when Bryant should be promoted to the majors so overblown. For all of the talent on hand, it will take time for these youngsters to find their way at the major league level. The offense may be full of potential impact players, but the rotation behind Lester—Jake Arrieta, Jason Hammel, Kyle Hendricks and Travis Wood—does not yet appear to be playoff-caliber even in the wake of Arrieta's breakout season in which he went 10-5 with a 2.53 ERA at age 28. That quartet has exactly three qualified seasons with an ERA+ above 100 between them.

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​X-Factor: Starlin Castro

As the new wave of talent arrives, Castro, who turns 25 on March 24, already ranks as an elder statesman; in fact, he is the longest-tenured Cub. How much longer he'll hold that ranking is unknown, in part because blue-chip shortstop Addison Russell—who enters the year as a top-five prospect by Baseball America, Baseball Prospectus and MLB.com—is rising quickly through the farm system, and Bryant, Baez and perhaps Alcantara could be factors at the two neighboring positions. After slipping to a career-worst .245/.284/.347 in 2013, Castro rebounded to bat .292/.339/.438 and tied his career high of 14 homers last season, making his third All-Star team. He also avoided the kind of high-profile mental mistakes that previously led to benchings.

It wasn't all roses, however. Castro stole a career-low four bases and was seven runs below average in the field via Defensive Runs Saved, and saw his season end in early September due to a high ankle sprain. In all, his 2.0 WAR showing was adequate but hardly exceptional, and the reality is that he has been worth just 1.4 WAR over the past two seasons after accumulating 8.0 over his first three. While he's signed through 2019 with a club option for '20, this will be a pivotal year for Castro. Either he will build on his bounce back campaign and write himself into the Cubs' future, or he'll head into the next offseason as a potential trade target.

Number To Know: 24.2%

That's the rate at which Cubs hitters struck out in 2014, the third-highest in major league history behind only the '13 Astros (25.5%) and '10 Diamondbacks (24.7%). While it's easy to overlook the high rates of Mike Olt (38.8%) and Junior Lake (33.7%), given that they were lineup placecholders who don’t have much future with the team, it's worrisome that Baez whiffed an astounding 41.5% of the time and walked in just 6.6% of his plate appearances. That unsustainable ratio could have him summering in Iowa again if he fails to improve.

Red Sox, Mets, Cubs among potential playoff surprise teams for 2015

Likewise, Alcantara struck out in 31% of his PA, and Soler in 24.7%, both while walking with roughly the same frequency as Baez. Down on the farm, Bryant whiffed in 27.2% of his PA as well. Those players do provide pop and more than a little speed, but they won't be able to utilize their attributes if they can't make contact. With that much swinging and missing, the Cubs' offense, which ranked just 12th in the league last year at 3.79 runs per game, will again struggle to score runs.

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Scout's Takes

Most Overrated: Javier Baez

“It's hard to have consistent success when you're striking out at that alarming rate. It has to be a concern. I hope he doesn't strike out more than his batting average. He could strike out 200 times and hit 20-plus home runs.”

Most Underrated: Jake Arrieta

“He always had good stuff, but he improved his fastball command, a key for any starter. There's no reason to believe he can't pick up where he left off last year. I think he'll be a solid No. 2, No. 3-type starter.”