Right-hander Tyler Glasnow (No. 27), outfielder Austin Meadows (No. 45), shortstop Alen Hanson (No. 67) and outfielder Josh Bell (No. 74) rounded out the Bucs on a list whose main components are being close to making the Majors and making a big impact once there.
The annual ranking of baseball's biggest and brightest young talent is assembled by MLBPipeline.com Draft and prospect experts Jonathan Mayo and Jim Callis, who compile input from industry sources, including scouts and scouting directors. It is based on analysis of players' skill sets, upsides, proximity to the Majors and potential immediate impact to their teams. The list, which is one of several prospect rankings on MLBPipeline.com's Prospect Watch, only includes players with rookie status in 2014.
Polanco, the 22-year-old Dominican native who has dibs on PNC Park's right field, scores high on "proximity" and "impact."
Described by Pirates manager Clint Hurdle as "a young Darryl Strawberry" -- invoking the lanky left-handed swinger who had 280 homers and 201 stolen bases through his age-29 season until injuries and off-field problems marred his career -- Polanco has spent the winter collecting compliments and honors.
The latter included both the Rookie of the Year and Most Valuable Player Awards in the Dominican Winter League, where Polanco sparked Escogido to a league-best 31-19 regular-season record by hitting .331 and reaching base 42.8 percent of the time.
The plaudits have come from all over. MLB Network's Peter Gammons calls Polanco's breakout the "single most significant winter ball story." A rival National League GM foresees the coming Starling Marte-Andrew McCutchen-Polanco alignment as "the best outfield in the league."
The Pirates are committed to having Polanco, who has a grand total of only nine Triple-A at-bats, start the season in Indianapolis. That puts him on the same timetable as Marte, who in 2012 gained three months of Triple-A seasoning before a late-July big league debut.
Similarly, Taillon is a candidate to be Gerrit Cole 2.0. Cole checked in last June after a dozen Indianapolis starts, and Taillon could be the rotation's next midseason jolt, if he continues to progress in several key areas.
"It depends on the development of his offspeed pitches," pitching coach Ray Searage said after checking out Taillon during the Pirates' recent voluntary workouts in Bradenton, Fla. "He needs to throw them for strikes. We've got to see how he pitches in April and May, but he's promising."
While Polanco is a newcomer on the 40-man roster and Taillon will be in Spring Training on an invite -- as will Hanson -- the three other cited prospects will not be in camp, since they are early in their development.
Glasnow, 20, put himself on the map with an eye-catching season for Class A West Virginia. The 2011 fifth-round Draft choice went 9-3 with a 2.18 ERA in 24 starts, piling up 164 strikeouts in 111 1/3 innings.
Meadows' ranking bears out his pre-Draft reputation as the high school player closest to being big league ready. After being the Bucs' highest choice in last June's First-Year Player Draft, at No. 9 overall, the 6-foot-3, 200-pound lefty hit .316, with an on-base percentage of .424, in 48 games between Rookie and A-ball.
Meadows thus leapfrogged Bell, the multisport star whose 2012 pro debut was cut dramatically short by a severe knee injury. Bell took nearly a year to recover, and put in a full 2013 season with West Virginia, displaying terrific gap power (37 doubles).
Hanson remains the most fascinating infield prospect in the Pittsburgh system. He has put in four full seasons in the Minors, yet does not turn 22 until late October. The athletic Dominican has battled consistency in the field (committing an error about every three games) and his prospects as the Pirates' future shortstop may well depend on how he responds to his first Triple-A exposure.