A baseball player can work on his hitting ability. A baseball player can work on his fielding prowess. A baseball player can work on his base-stealing skills, or numerous other secondary aspects of his offensive or defensive game; but he either has the ability to drive balls over the fence or he doesn't—and you can't teach that.
Power is often a double-edged sword, though, as that power too often comes with its own drawbacks: namely, a low batting average and a tendency to swing and miss too often. Wily Mo Peña, MLB/MiLB outfielder and DH in the 2000s, personified both the upside and the drawbacks of that kind of profile.
After the Mets signed Peña in July 1998, MLB voided the 16-year-old's contract a few months later when complications arose surrounding the authenticity of the parental signatures provided. A few months later, Brian Cashman signed the young Dominican, giving him a $2.3 million signing bonus, then the largest bonus given to a rookie prospect. The money was seemingly well worth it, as the 17-year-old hit .247/.323/.446 for the GCL Yankees and was rated the 88th-best prospect in baseball going into 2000. A year later, the Yankees traded Peña to the Cincinnati Reds for farmhands Michael Coleman and Drew Henson, neither of whom ever had any real MLB impact.
In the Reds' farm system, Peña bloomed, hitting a combined .260/.329/.445 over the next two years and earning a cup of coffee with the big league team in 2002. From 2003 to 2005, he was used mostly as a fourth outfielder, getting time in right field and center. In 2003, he hit a somewhat disappointing .218/.283/.358 in 181 plate appearances, but improved, hitting .259/.316/.527 with an impressive 26 home runs in 364 plate appearances in 2004 and .254/.304/.492 with 19 home runs in 335 plate appearances in 2005.
At the beginning of the 2006 season, the Reds traded Wily Mo to the Boston Red Sox for Bronson Arroyo, where Peña continued serving as a fourth outfielder. In his first year with the Red Sox, the 24-year-old had another respectable showing, hitting .301/.349/.489 in 304 plate appearances; but after a lackluster first half in 2007 that saw him hit .218/.291/.385 in 172 plate appearances, the Red Sox shipped him off to the Washington Nationals in a three-team deal. Peña hit well for the Nats in the second half, slashing .293/.352/.504 in 145 plate appearances, but after hitting a paltry .205/.243/.267 in 206 plate appearances in 2008, the Nationals designated him for assignment and placed him on waivers. Peña went unclaimed and declined his assignment, making him a free agent.
Over the next few years, Peña played all over the place, looking to slug his way back onto a major league roster. In April 2009, Omar Minaya signed the 27-year-old to a minor league deal, making Wily Mo a Met once again (or technically for the first time, depending on how you look at it); however, the Mets released him a few months later after hitting a lackluster .276/.296/.414 with the Buffalo Bisons. After a stint with the Bridgeport Bluefish of the independent Atlantic League, Peña signed a minor league deal with the San Diego Padres and was assigned to their AAA affiliate. He hit .314/.390/.556 in 40 games with the Portland Beavers in the run-happy PCL, but failed to crack the Padres' roster in September.
At the start of the 2011 season, the Arizona Diamondbacks signed the 29-year-old to a minor league contract with an invitation to spring training. Though he failed to crack the Opening Day roster, Peña forced his way into the Diamondbacks' lineup in mid-June after hitting .363/.439/.726 with the Reno Aces. The result was predictable: Wily Mo hit .196/.196/.522 in 46 plate appearances with Arizona, and was designated for assignment and released roughly a month later. The Seattle Mariners decided to try their hand with Peña, signing him to a minor league contract a few days later. Peña impressed with the Tacoma Raniers, hitting .333/.443/.637 in 13 games, but couldn't replicate this production when called up to the big league team, hitting .209/.284/.343 in 22 games with the Mariners at the end of the year.
After finding no interest among MLB teams and wanting a more lucrative deal than an independent team would be able to offer, Peña packed his bags and headed out to the Land of the Rising Sun. The Fukuoka SoftBank Hawks, looking for a gaijin to provide a power boost to their lineup, signed the 30-year-old to a two-year contract worth roughly $3.5 million. The offense-dampening standardized ball introduced in 2011 seemingly had no effect on the Dominican slugger, who hit a hefty .280/.339/.490 in his debut year with the Hawks. His 21 homers were fourth in the Pacific League and the most on his team; by comparison, third baseman Nobuhiro Matsuda tallied the second most on the team with 9 dingers.
The 2013 season was a different story. Plagued by pains in his right knee, Peña was limited to just 55 games, and hit a paltry .233/.322/.307 when he was able to play. Peña saw intermittent playing time early on, and then missed a large chunk of time in the middle of the season after being removed from the active roster to have his meniscus repaired after surgery on it in mid-August. By the end of the season, the Hawks decided against bringing the slugger back for a third year. In December 2013, the Orix Buffaloes announced that they inked Peña to a one-year deal with roughly $1 million, plus incentive bonuses. He would be replacing Dae-Ho Lee at first base—just, rather ironically, as the Hawks signed Lee to replace Wily Mo Peña
That offseason, Peña did extensive conditioning on his lower body, working on running and leg-lifting exercises to help rehab his ailing knee. The time and exercise did him good, as the 32-year-old rebounded to post another solid season, hitting .255/.344/.486 with 31 home runs, the most on the Buffaloes and third-most in the Pacific League.
At the end of the season, Peña was diagnosed with inflammation in his right pectoral muscles, and was taken off of Orix's active roster. His injury supposedly angered Buffaloes management, as it meant he would not be able to return in time to help the Buffaloes in the playoffs. Coupled with what the team saw as sub-par numbers, management soured on the Dominican slugger. After Peña and Orix management were unable to come to an agreement about his future with the team later in the year (Peña was reportedly looking for a multi-year contract and roughly $1 million more than the Buffaloes were offering) the Buffaloes left Peña off of their reserved list, making him a free agent.
Among his current suitors are the Rakuten Eagles, who see him as a candidate to replace Andruw Jones, and the Minnesota Twins, who see him as a cheap and easy way to add a right-handed power hitter to their lineup. While the Eagles' offer might be more appealing in the long-term—as they are considering offering the soon-to-be-33-year-old slugger a multi-year contract—the opportunity to return to MLB is an intangible benefit that cannot be quantified in money alone.
The question is whether or not Peña can replicate any of the success that he had in Japan, thereby making him a somewhat valuable commodity for an MLB team. His low batting average and on-base percentage have always been his biggest impediments to a successful MLB career, and I am not sure if, despite his success in Japan, that will change. Shortly after he signed with the Hawks in 2012, Peña told Nikkan Sports that his game plan was different: "I am not going to think about hitting home runs," he said. "I just want to make contact...I want to see as many pitches as possible from as many different pitchers." While he did draw 35 walks and posted a respectable .339 OBP, his walk total was only marginally better than that of some of his earlier major and minor league seasons. The fact that he drew a comparable number of walks in more games means that his walk rate actually shrunk. Peña did improve in 2014, drawing a career-high 59 walks; but that total remains an outlier.
Defensively, the metrics never treated Peña kindly. In limited time in both corner outfield positions, he was not particularly well-liked by either Total Zone or UZR, as was the case in the more limited amount of time he spent as a backup centerfield. Having since transitioned to first base, Peña's lack of defensive prowess will hurt his value less, but will put more of an emphasis on his already-questionable bat to provide some value.