Johan Herrera, a 17-year-old third baseman from the Dominican Republic, has signed with the Pirates for $300,000.

Herrera, who is 6-foot-1, 190 pounds, stands out for his lefthanded power. He has an average arm but his bat is ahead of his defense, so there's a chance he may end up changing positions. Herrera trained in Bani with his uncle, Juan Herrera, who is known in the Dominican Republic as "Mon," and was represented by Jim Sanson and former Red Sox scout Luis Scheker. 

Since July 2, the Pirates have also signed Dominican third baseman Julio de la Cruz for $700,000 and Dominican outfielder Michael de la Cruz (no relation to Julio) for $700,000.