Herrera happy to change role with contending Nats
MLB Trade: Nationals acquire veteran reliever Kelvin Herrera from Royals
New Washington Nationals' reliever Kelvin Herrera introduced to D.C. - Federal Baseball
Rosenthal: Why were the Royals so quick to deal Kelvin Herrera? - The Athletic
Report: White Sox sign Kelvin Herrera as they wait for Bryce Harper and Manny Machado decisions
MLB trade deadline: Washington Nationals get Kelvin Herrera from Royals for 3 prospects
Royals trade Kelvin Herrera, Washington Nationals
KC Royals Great, Kelvin Herrera, bids farewell to baseball
In Kelvin Herrera, Nationals may have added the final piece of a true postseason bullpen
Nationals acquire closer Kelvin Herrera from Royals
What the Kelvin Herrera trade means for the Yankees - Pinstripe Alley