The 45-man provisional roster has only three players listed at catcher: veterans Miguel Olivo of the Royals, Ronny Paulino, now of the Phillies, and Castillo.
But while the 24-year-old Castillo lists catcher as his primary -- and favorite -- position, he's also a legitimate second baseman. And shortstop. And he has seen time at third base and the outfield this past year.
"The most impressive thing about him is his versatility," said Terry Reynolds, the Reds' director of player development. "He can play every position on the diamond and gives a manager a lot of options, whether to come off the bench and play in the middle of the diamond or come in and catch. It's a nice luxury."
Castillo joined the Cincinnati organization last August as one of the three players acquired from the Arizona Diamondbacks for slugger Adam Dunn. After hitting .254 with six homers and 47 RBIs in 104 games at Triple-A Tucson before the deal, he played briefly at the Reds' Triple-A Louisville affiliate before making his big league debut and hitting .281 in 18 games with Cincinnati.
Coming up through the Arizona system, Castillo was regarded as one of the top defensive catching prospects as well as an exciting high-energy player to watch. After making his professional debut at first base in 2003 in the Dominican Summer League, he moved up through the organization, enjoying his best year in 2007 when he earned Southern League All-Star honors by hitting .302 with six homers, 46 RBIs and 18 steals at Mobile.
"The interesting thing about Wilkin is, I'd go into Mobile for a three-game series and I'd see him catch one day, play shortstop the next and go second-to-third on the third," Diamondbacks farm director A.J. Hinch said at the time. "I don't know if there's another player in baseball that can do that."
A .281 hitter over six Minor League seasons, Castillo grew up playing shortstop as a kid in the Dominican before moving behind the plate when he was 15.
"I'm confident in my ability to play any position and I feel comfortable playing anywhere," he said. "But I feel most comfortable catching because I think I can go further in the game with it."
Reynolds hasn't been given any indication by the Dominican Republic's representatives as to what the odds will be that he will have his catching prospect in camp in March.
"Who knows, to be honest, how they're going to pick their team?" he said. "But when it comes to having a guy who can play eight different spots, that certainly helps."
He thinks it also will likely help Castillo down the road in Cincinnati with manager Dusty Baker.
"When he comes into camp, I'd guess he'll get a look at a lot of different spots, but I would think that ultimately he'll be a 'super-utility' type of guy," he said. "A lot of guys have played a long time in the big leagues in that kind of role."
Of the 17 members of the Reds organization on provisional Classic rosters, 10 are Minor Leaguers, with only Castillo having any big league time under his belt.
Other Reds on Classic rosters
RHP James Avery
is on the Canadian provisional roster. The 24-year-old from Moose Jaw, Sask., spent the last two seasons at Double-A Chattanooga, going 7-8 with a 4.89 ERA in 24 starts while striking out 92 over 130 2/3 innings last summer.
SS Yen-Wen Kuo is on the Chinese Taipei provisional roster. A defensive whiz, the 20-year-old hit .281 with 15 RBIs in his debut in the Gulf Coast League last summer.
RHP Kyle Lotzkar is on the Canadian provisional roster. The 19-year-old, a 2007 supplemental first-round pick, posted a 3.58 ERA in 10 starts at Class A Dayton in 2008 but missed time with a fractured elbow.
RHP Luis Machuca is on the Panamanian provisional roster. In four seasons in the Venezuelan and Dominican Summer Leagues, capped by four starts in the Gulf Coast League down the stretch last summer, the 20-year-old had marked success, combining to go 16-8 with a 2.86 ERA.
LHPs Luca Panerati and Matteo Pizziconi are on the Italian provisional roster. Two of Team Italy's young aces in international play the last few years, the 19-year-old southpaws hail from Grossetto and Anzio, respectively. Panerati posted a 2.84 ERA in 10 relief appearances in the Gulf Coast League last summer, while Pizziconi was 3-0 with a 0.70 ERA in 15 games there.
LHP Alexander Smit is on the Netherlands provisional roster. The 23-year-old, acquired by Cincinnati on a midseason waiver claim in 2007, has been a staple of the Dutch pitching staff for several years, having pitched in both the 2006 World Baseball Classic and the 2008 Olympics. He's combined for a 3.49 ERA over a six-year career, though he's yet to pitch above the Class A Advanced level. Last summer, he was 8-7 with a 3.87 ERA and 94 strikeouts over 111 2/3 innings at Sarasota.
RHP Juan Carlos Sulberan also is on the Netherlands provisional roster. The 19-year-old from Curacao pitched for the Dutch Olympic team last summer and looks to make his pro debut in 2009. He moved to the United States in high school and was taken by the Reds in the 30th round of the 2008 Draft after going 11-0 with a 1.40 ERA in Florida.
LHP Philippe-Alexandre Valiquette is on the Canadian provisional roster. Could 2008 have been the breakthrough season the Reds have been looking for from Valiquette since drafting him in the seventh round in 2004? The Montreal native has a 5.02 career ERA but combined between two Class A stops in '08 to strike out 65 batters in as many innings. He posted a 3.12 ERA at Dayton and a 3.92 ERA at Sarasota.