The Washington Nationals have acquired right-handed reliever Kelvin Herrera from the Kansas City Royals for three prospects. The Royals are acquiring outfielder Blake Perkins, third baseman Kelvin Gutierrez and right-handed pitcher Yohanse Morel for Herrera, one of the most desirable bullpen arms available. Herrera has 14 saves and a 1.05 ERA this season for the … Read more