The Washington Nationals agreed to terms on a one-year contract with a mutual option for 2020 with first baseman Matt Adams on Tuesday. Nationals President of Baseball Operations and General Manager Mike Rizzo made the announcement.
Adams, 30, returns to the Nationals after hitting .257 with nine doubles, 18 home runs, 48 RBI, 24 walks and 37 runs scored in 94 games with Washington in 2018. He recorded a .510 slugging percentage and an .842 OPS before being traded to the St. Louis Cardinals on Aug. 21. In 121 games between the two clubs, he clubbed a career-high 21 home runs while recording 57 RBI and a .477 slugging percentage.
As a member of the Nationals, Adams posted a .538 slugging percentage against right-handed pitchers, good for eighth among National League hitters (min. 230 PA vs. RHP) at the time of the trade. Of his 21 home runs in 2018, 20 came at the expense of right-handed pitching. Across his career, 83 of his 96 career homers have come against right-handed pitchers.
While in Washington, Adams saw action at first base (48 G), left field (15 G) and right field (1 G). When he took the field as a starter in 2018, the Nationals posted a 37-22 (.627) record. In those 59 starts, he hit .269/.339/.546 with nine doubles, 17 home runs and 42 RBI.
Adams has proven to be a valuable contributor off the bench in his career. His nine career pinch-hit home runs and 47 career pinch-hit RBI are the most among active players. 
In 26 games of Postseason experience as a member of the St. Louis Cardinals, Adams hit .226 with three doubles, four home runs, 11 RBI and 10 runs scored as the Cardinals advanced to the World Series in 2013 and the National League Championship Series in 2014.
Adams has a career .470 slugging percentage that ranks ninth among National League left-handed batters since his debut in 2012. He has clubbed 113 doubles, six triples, 96 homers and 332 RBI across seven Major League seasons. He was originally selected by St. Louis in the 23rd round of the 2009 First-Year Player Draft out of Slippery Rock (PA) University.
With this transaction, Washington's 40-man roster is at 39 players.