Ruiz, a 22-year-old right-hander, is the No. 3 international prospect in baseball, according to MLBPipeline.com.
In three seasons pitching in Cuba's Serie Nacional -- he debuted in 2012 as an 18-year-old -- Ruiz went 24-17 with a 2.55 ERA in 60 games (55 starts). Ruiz also pitched in the Dominican Winter League this year, making three starts for Aguilas and going 2-1 with a 3.77 ERA.
David Adler is a reporter for MLB.com based in New York. Follow him on Twitter at @_dadler. This story was not subject to the approval of Major League Baseball or its clubs.