Emilio Bonifacio is the Cubs' newest rent-a-scrub and he's worked out very well so far. The slap hitter is sporting a .330 batting average and is tied for fifth in the major leagues in steals. He'll be noticeably less useful after the BABIP dips well below .400, but he has been a spark plug atop the Cubs' lineup thus far. Bonifacio is a pretty good guy to have around as a bench player because of his defensive utility, switch-hitting ability, and speed. Expecting him to be a full-time leadoff hitter is asking too much, but the Cubs can afford to ride the hot hand as they rebuild.
Luis Valbuena is a left-handed infielder that primarily plays third base, but has increasingly been used at second base for the Cubs, where replacement-level hitting is in great demand. Valbuena has some power and draws a good amount of walks, but when Adam Dunn has hit .220 more recently than you, you're doing something wrong. Former popular trade target Mike Olt platoons with Valbuena at third base. Olt has flashed some power on the big stage, but unfortunately that power comes attached to a 35.7 percent strikeout rate.
The biggest disappointment for the Cubs last season was not the number of losses, but the performance of key building blocks Starlin Castro and Anthony Rizzo. There were still encouraging signs amid Rizzo's growing pains last season. He hit 23 homers, smacked 40 doubles, and drew 76 walks while not striking out excessively, so there's at least some case to be made that the hits just weren't falling in. Rizzo is supporting the "bad luck" theory with his excellent hitting thus far this season. There is still plenty of hope that the 24-year old will emerge as one of the league's best first-sackers.
In 2013, Starlin Castro led the National League in at-bats for the third straight year, despite his triple-slash line comparing only slightly favorably to that of Jeff Keppinger. Oof. He has the raw ability to be a consistent .300 hitter and (in part) blames his struggles from 2013 on a lawsuit tying up $3.6 million. Like Rizzo, Castro's year-to-date performance in 2014 has been very encouraging as his batting average and power have come back in full force. His defense has even improved to "passable", despite his propensity to botch the occasional easy one. It's not hard to envision a future in which he's equal parts good and frustrating.
Hitting behind these two 2014 success stories is platoon outfielder Nate Schierholtz. He's very good at slugging righties, and, well, not much else. Schierholtz is off to a horrendous start this season with no home runs and only three walks through about 100 plate appearances. He'd be great fit for a contending team with a bench outfielder that crushes lefties, but instead he plays for a bottom-feeder with bench guys that can't hit anyone and has batted cleanup in half the games. Cubs!
Junior Lake is an outfielder so toolsy that it's a shock he's never played for any White Sox minor league affiliate. He has great speed, a superb throwing arm, and plenty of raw power, but he still needs to prove he can translate the physical ability into results. This season, Lake has delivered an extra-base hit roughly once every 10 plate appearances, so the power is evident. The next step will be for the free swinger to improve his selectivity at the plate. Like most players with his profile, the range of possible outcomes is wide. He might be a key cog on the next competitive Cubs team, or he might be just a guy.
Last season was a failure for a variety of reasons for the North Siders, but Welington Castillo's season was a pretty nice development. He doesn't draw rave reviews for pitch framing and is just so-so at controlling the running game, but ranks pretty good against his catcher peers with the lumber. Castillo gets on base at an above-average clip and has shown enough power to keep pitchers honest. Above-average offense from a cost-controlled catcher is a great thing to have.
Over the course of 2012 and 2013, Darwin Barney made just seven errors while starting the vast majority of games at second base for the Cubs. Whatever your thoughts on Barney or errors as a statistic, that kind of sure-handedness at the keystone is very, very impressive. His bat, however, has been in steady decline over the course of the past four seasons. Barney was never a good hitter to begin with, so the question of whether his defense can support playing him on a regular basis is getting progressively more uncomfortable.
The Cubs' rotation is anchored by Jeff Samardzija, who has looked like nothing short of an ace thus far this season. It's worth noting, however, that his strikeouts are down and that he wore down as last season went along. Shark has these dominant stretches when he seems untouchable, but so far in his career as a starter, he's been very inconsistent. He's prone to the occasional game where he gets tagged hard and doesn't leave the offense (particularly one as weak as that of the Cubs) much of a chance. Last season, he allowed one or zero earned runs nine times, but allowed five or more earned runs eight times.
Such inconsistency draws comparisons to Edwin Jackson, who has contributed plenty of headaches to the Cubs and their fans. Jackson looked like a complete flop in 2013, but in reality he was pretty much the same pitcher he's always been; he just had the league's lowest strand rate. Jackson's low-mid 90's fastball is actually quite hittable, so he lives and dies by how well he commands his best offering, the slider. This season, his control has deserted him and he's walking more hitters than he has since his Tampa Bay days. The results haven't been good so far, but the strand rate is still pretty low, so he's a reasonable bet for a rebound.
Travis Wood is the resident lefty in the Cubs' rotation and he's followed up last year's strong showing with a great start to 2014. Since putting on a Cubs uniform, Wood has increasingly relied on his cutter and the result has been a lot of weak contact. This season, Wood's cutter has induced more whiffs and ground balls than in the past, so it's possible 2014 will represent another step forward.
Orioles castoff Jake Arrieta put on a Cubs uniform in the middle of last season after being shellacked for much of his career in Baltimore. His rate of base hits allowed mysteriously dropped after the trade and it's pretty safe to assume that it was attributable to plain old good fortune. Arrieta has battled control issues throughout his career and his strikeout rate was very pedestrian as a member of the Cubs. He pitched very well in his first start of the season against St. Louis, but any optimism about the 28-year old must be extremely cautious.
The Cubs' have yet to officially name a permanent closer for the time being, but Hector Rondon seems like a pretty safe bet to lock down the job. He's had the most success of any Cubs reliever and has been able to miss bats without the walk problems that Justin Grimm and Pedro Strop have had. Rondon has had Tommy John surgery and was subsequently acquired by the Cubs in the Rule 5 draft prior to the 2013 season. He doesn't use his off-speed pitches all that frequently and instead mixes in his mid-90s fastball with a cutter and a sinker.
Outlook & Prediction: The Cubs have had some nice pitching performances this season from Samardzija, Wood, and Jason Hammel (who the White Sox won't face), but ultimately won't score enough runs to win many games even if Castro and Rizzo continue their good seasons. Predicted record and finish: 70-92, fifth place, NL Central