Yost, 54, who managed the Brewers from 2003 to Sept. 15, 2008, was dismissed when the club had an 83-67 record and was in second place. During his tenure, Milwaukee had a 457-502 record, and his highest finish was second in 2007, with an 83-79 record.
From 1991-2002, Yost was a coach for Atlanta, serving eight years as bullpen coach and four years as third-base coach for Braves manager Bobby Cox. A catcher, Yost played in the Majors from 1980-85 for Milwaukee, Texas and Montreal.
"He'll be a resource for our Major League staff and our Minor League Department," said Royals general manager Dayton Moore. "He'll do some scouting for us as well. He'll be a tremendous asset for us. He has a lot of experience and is an outstanding baseball man."
Moore said there are no plans to have Yost on the field with the Major League club to assist manager Trey Hillman during Spring Training.
"He may get on the field and do some things, but if he does, it'll be more on the player-development side. He'll be down at the early camp," Moore said. "He and Trey have a very close relationship."
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.