"I'm sure there's a more detailed plan, but we're taking it one step at a time until the paper work is done," Farrell said. "Whether that begins in Fort Myers, [Fla.,] timeline of available games and who's still playing, who's in the playoff stretch, all of those will be factored in."
Once he finally makes his ascent to the Major Leagues, Castillo will have a mentor in Red Sox slugger David Ortiz, who said he's looking forward to playing alongside someone who seems like a "great kid."
"Those players from Cuba, at that stage, they know how to deal with things," Ortiz said. "They know what they're doing and that's why they come up to the big leagues and perform at the highest level. It's good for him to have guys like myself, Spanish speaking, where I can help him with some things and get him comfortable around here."
Castillo, who hasn't played a game in nearly a year and a half after being suspended following his first defection attempt, played five seasons in Cuba's Major League, Serie Nacional, posting a career on-base percentage of .383, a .516 slugging percentage and an .899 OPS.
Jamie Ross is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.