He worked for the Rays as an instructor for a couple years before coming on as the team's bench coach after the 2007 season, working under Joe Maddon.
In 2008, he became the bench coach for the Tampa Bay Rays.
The 53-year-old Martinez, who played in the majors from 1986 to 2001, joined the Cubs' staff after the 2014 season.
Cubs bench coach Dave Martinez has scored his first gig as a major-league manager.. More news: China has world's 136th most powerful passport, 69 spots behind Taiwan
David Ross didn't exactly ride off into the sunset once Cubs teammates Anthony Rizzo and Jason Heyward picked him up onto their shoulders and carried him off the field after last year's World Series Game 7 in Cleveland. But while the money behind Martinez's deal is not immediately clear, the length of the deal signals recognition of the state of the managerial market (Cora and Ron Gardenhire got three years each to manage the Red Sox and Tigers, respectively).
An apprenticeship under Joe Maddon is a legitimate strength on a managerial resumé, and there's no particular reason this won't work.
The Nationals record of postseason underachievement has been mostly about the players, due in equal parts to health and general struggles on the biggest stage.
But the Nationals did not struggle to negotiate with their manager this time, committing three years (and perhaps a fourth) to Martinez in a marked departure from their normal handling of managers. He has interviewed for several openings in recent years, including the Nationals job four years ago, but to date has not been selected.