Castillo, 26, hit .274 with eight home runs in 113 games this past season.
He missed the final six games of the season.
---Wally Joyner was hired as the Detroit Tigers hitting coach, according Foxsports.com.
Earlier in the day, Joyner sgepped down from his job as the assistant hitting coach for the Phildelphia Phillies.
---The Kansas City Royals signed 24-year-old catcher Francisco Pena to a minor league contract, MLB.com reported.
The Mets signed Pena out of the Dominican Republic when he was 16 years old for a bonus of $750,000. But Pena, the son of former major league All-Star Tony Pena, has struggled in the minors.