The annual ranking of baseball's biggest and brightest young talent is assembled by MLB.com's Draft and prospect expert Jonathan Mayo, who compiles input from industry sources, including scouts and scouting directors. It is based on analysis of players' skill sets, upsides, closeness to the Majors and potential immediate impact to their teams. The list, which is one of several prospect rankings on MLB.com's Prospect Watch, only includes players with rookie status in 2013.
After a shift from third base to the outfield, a .405 average for half a season at Class A Lakeland, a Futures Game MVP performance and a slow finish, Castellanos actually fell in the rankings from No. 10 at the end of last season to No. 21 heading into this one. It was a surprising slide, with prospects previously ranked in the teens passing him on the list, but it still leaves him among the best on the cusp of the big leagues, and by far the best prospect in a Tigers farm system better known for pitchers in recent years.
Castellanos was one of the top third-base prospects in last year's rankings. Had he stayed at the hot corner, his standing would've ranked him second among third-base prospects behind only Minnesota's Miguel Sano, and just ahead of Texas prospect and fellow Futures Game participant Mike Olt. As an outfielder, he ranked No. 6 at his position.
The shift away from the infield, borne out of Prince Fielder's arrival in Detroit and Miguel Cabrera's move to third, came just after Castellanos' three-hit performance in the All-Star Futures Game at Kauffman Stadium, where the 20-year-old cleared the center-field fence for a signature highlight home run. Once that was decided, Castellanos spent most of the second half focused on the adjustment, getting used to right field at Double-A Erie before giving left field a try in the Arizona Fall League.
Defensively, the learning process essentially made last year a split of two different seasons for the Tigers' top pick in the 2010 First-Year Player Draft. Offensively, it was a different split, one that Tigers officials believe came from the rigors of a long year.
Castellanos spent much of the season's first half leading all Minor League hitters in batting average. He took his hitting groove with him to Erie and stayed on his hitting tear for more than a month, batting .303 in 21 games for the SeaWolves in June and then .318 in 27 games in July.
While speculation grew rampant about Castellanos' chances at a September callup to give the Tigers another right-handed hitter in the outfield, the final month of the Minor League season seemed to take its toll. The extended season in instructional ball and the AFL arguably compounded it.
"I think towards the end of the season, Nick got a little tired -- and somewhat even mentally," Tigers vice president and assistant general manager Al Avila said last week. "He went through the Minor Leagues real fast, and then jumped into the Arizona Fall League with very little rest. And he even went to Lakeland before going to Arizona to work on certain things in the outfield. So I think by the time he got to Arizona, mentally, physically, I think for a high school kid, that's a lot. And so a good rest for him, that's what he really needed."
At this point, the regard for Castellanos as a Major League hitter in the making is just about a consensus. It's where he'll play, and whether he'll hit for power, that remains to be answered.
"He can flat-out hit, adjusting extremely well to any and all pitching," the MLB.com scouting report reads. "He drives the ball to all fields and while he hasn't shown too much in the way of home run power to date, there is definitely pop in his bat that will come."
Though Castellanos will get his chance to battle for a job in left field in Spring Training and try to crash the roster like Rick Porcello did the rotation four years ago, he'll likely start the season playing left field at Triple-A Toledo. By contrast, the timetable on Rondon is far more aggressive. In Rondon's case, his rise to 92nd on MLB.com's list coincides nicely with the Tigers' need for a closer.
Rondon never ranked very high on Tigers prospect lists, despite a fastball clocked at 100-plus mph, until his command and secondary pitches improved to back up his heat, taking him from a hard thrower to legitimately nasty pitcher. The result was a breakout campaign that gave the Tigers their best relief prospect since Joel Zumaya converted from starter in 2006.
Rondon, who turned 22 last month, racked up 29 combined saves at three different Minor League levels, rising from Lakeland to Erie at midseason before an August stint in Toledo. He allowed just 32 hits over 53 innings, with 26 walks and 66 strikeouts.
Rondon ranked behind other young relievers who made it to the Majors down the stretch last season, such as hard-throwing Cardinals righty Trevor Rosenthal. However, none of Rondon's counterparts have a better inside track towards a closer's job this spring. Rondon not only has an invite to camp, he has no established closer to challenge him. Tigers president and GM Dave Dombrowski described him as the leading candidate for the job that opened up when the Tigers let Jose Valverde walk as a free agent.