Free-agent outfielder Brett Gardner, the New York Yankees' longest-tenured player, will remain with the team after reaching a one-year, $12.5 million deal, a source confirmed to ESPN's Buster Olney on Thursday.

The deal breaks down with Gardner getting a $2 million signing bonus and an $8 million salary for next season. The Yankees have a $10 million option for 2021 with a $2.5 million buyout, a source told ESPN's Jeff Passan.

Gardner made $7.5 million last season. The New York Post first reported the agreement.

His agreement, added to the pending nine-year, $324 million contract with pitcher Gerrit Cole, raises the Yankees' projected payroll for the luxury tax to about $257 million -- $9 million above where the highest surtax starts.

The 36-year-old Gardner, a rare lefty in a Yankees lineup dominated by right-handed hitters, recorded his best season in 2019, when he hit .251 with a career-high 28 homers and 74 RBIs.

"The constant that he is means a lot to the organization as well as the production on the field," assistant general manager Mike Fishman said.

Gardner originally was slated to be the Yankees' fourth outfielder last season, but he was called on to start 141 games -- mostly in center field -- because of a series of injuries to Aaron Judge (102 games played), Aaron Hicks (59) and Giancarlo Stanton (18).

Hicks, who was slated to play center field in 2019, had Tommy John surgery after the season and is not expected to return until next summer.

Gardner was the Yankees' starting left fielder in all nine postseason games, going 6-for-34 with 4 RBIs and 15 strikeouts, as a record-setting power year by the Bronx Bombers ended with a string of K's and another October bust.

His signature moment last season came when he banged his bat against the dugout roof after being ejected in a game in July for arguing balls and strikes, leading Aaron Boone to take off on an expletive-filled rant that prompted the Yankees manager to call his hitters "savages" in the batter's box.

The team used the "savages" moniker for the rest of the season as a motivator.

"He is well loved by all his teammates," Fishman said. "The passion, it's a part of who he is."

Drafted by the Yankees in 2005, Gardner has a .260 career average with 124 home runs, 524 RBIs and 267 stolen bases in 12 big league seasons since 2008. His average of 4.25 pitches per plate appearance is third among active players with 3,000 or more plate appearances, behind only Matt Carpenter (4.27) and Mike Trout (4.26).

The Associated Press contributed to this report.