Calling him “one of the few most talented 19-year-olds in the world,” Red Sox general manager Ben Cherington introduced the team’s newest acquisition from Cuba, switch-hitting second baseman Yoan Moncada. Yoan Moncada, by far, received the richest signing bonuses for amateur players under 23 subject to baseball’s international signing pool : The club formally announced Moncada’s signing to a record $31.5 million deal on Thursday night after coming to terms with him on a deal Feb. 22. According to the certified public accountant representing Moncada, David Hastings, the other finalists for Moncada’s services were the Yankees , Dodgers and Padres .