Yost said after leading the Royals to an improbable pennant last season that he hoped to manage a few more years. His contract had been set to expire after the 2015 season.
Yost became the Royals' manager in May 2010 and presided over a massive rebuilding effort that culminated with the end of a 29-year playoff drought. The Royals took the San Francisco Giants to the seventh game of the World Series before their season finally ended.
The longest-tenured manager in club history, Yost will soon become its winningest. He has 373 victories, trailing only Dick Howser (404) and Whitey Herzog (410).
The Arizona Diamondbacks have agreed to a contract with Cuban pitcher Yoan Lopez that includes an $8.27 million signing bonus, two people with knowledge of the deal said. A hard-throwing 21-year-old right-hander, Lopez is expected to begin his Diamondbacks career in the minor leagues.