Wagner Mateo is 16-year-old Dominican center fielder that signed with the St. Louis Cardinals on July 2nd for $3.1 million.
He is working out in this video at a showcase/game set up by his agent, Edgar Mercedes, in Santo Domingo. The first at-bat is against probable 2nd-3rd round pick in this June's MLB Draft, Canadian left-hander Jake Eliopoulos.
Baseball Prospectus July 2nd Prospect Video
The video that is embedded in the articles of Kiley McDaniel at BaseballProspectus.com, in covering the July 2nd signing period of Latin American amateur baseball players.