Source: Nationals have three-year deal with Dave Martinez

The Nationals have an agreement in place with Dave Martinez to become the club's seventh manager, and despite his lack of experience they'll be giving him more job security than any of their previous six skippers.

Martinez and the Nats have agreed to a three-year contract with an option for a fourth year, a source familiar with the deal confirmed. A formal announcement isn't likely to come until later this week, after the World Series ends.

Martinez emerged over the weekend as the Nationals' likely choice to replace Dusty Baker from a limited field of known candidates that included former Red Sox manager John Farrell and Mets hitting coach Kevin Long. The 53-year-old former outfielder interviewed with general manager Mike Rizzo and members of the Lerner family on Thursday, according to sources.

The two sides hadn't negotiated a finalized contract as of Saturday night, but a source confirmed the finalized deal (which was first reported by The Washington Post) this morning.

In giving Martinez, 53, a three-year contract, Nationals ownership broke with longstanding (and controversial) form. Since the Lerner family purchased the club in 2006, no manager had been guaranteed more than two years, not even established and successful skippers like Baker and Davey Johnson.

That hard-nosed policy came back to haunt the Nationals two years ago when they initially selected Bud Black as their manager but saw negotiations break down and the veteran skipper walk away. Baker, who had been out of work for two seasons, wound up accepting a below-market, two-year, $4 million deal, creating a dilemma two weeks ago when the team suffered its second straight Game 5 loss in the National League Division Series with a manager whose contract was expiring.

The team made the surprising decision not to retain Baker, prompting criticism from many corners of the baseball community, then set about searching for someone who might be able to lift the franchise over its insurmountable October hump.

The Nationals interviewed Martinez and Farrell (who won the 2013 World Series with the Red Sox) and received permission to interview Long. They did not meet with Joe Girardi, the World Series-winning manager let go by the Yankees last week.

In the end, industry standards may have forced the Lerner family to move out of their comfort zone. The Red Sox and Mets each hired first-time managers and gave each of them three guaranteed years, establishing a baseline for negotiations with Martinez.

As Joe Maddon's bench coach for the last decade with both the Rays and the Cubs, Martinez has long been regarded a future manager around the sport. He has interviewed for several openings in recent years, including the Nationals job four years ago, but to date has not been selected.

A Brooklyn, N.Y., native of Puerto Rican descent, Martinez played in high school and college in Florida before he was drafted by the Cubs in 1983. He spent parts of 16 seasons in the majors playing outfield for the Cubs, Expos, Reds, Giants, White Sox, Devil Rays, Rangers, Blue Jays and Braves.