The 31-year-old is primarily a first baseman but also has played the outfield. He batted .226 with 20 homers and 56 RBIs in 333 plate appearances last year for the World Series champion Washington Nationals, hitting 12 of his homers in June and July.
New York has NL Rookie of the Year Pete Alonso at first.
Adams has 11 career homers and 49 RBIs as a pinch hitter, but he was just 3 for 33 as a pinch hitter last year — with two homers and a double.
An eight-year big league veteran, he also has played for St. Louis (2012-17, 2018) and Atlanta (2017), and he had his first stint with the Nationals in 2018.
Adams had a $3 million salary last year, and Washington declined his $4 million mutual option, which carried a $1 million buyout.