Moreland hit .203 with two homers and eight RBIs in 69 at-bats for San Diego, which acquired him from the Boston Red Sox on Aug. 30 for minor league outfielder Jeisson Rosario and third baseman Hudson Potts.
Moreland was 4-for-8 with an RBI in the playoffs.
The 35-year-old batted .328 with eight homers and 21 RBIs for the Red Sox and had $925,926 in prorated pay from a $2.5 million salary.
Moreland spent three seasons with the Red Sox and was an All-Star in 2018, when Boston won the World Series. His three-run, seventh-inning homer off Ryan Madson helped the Red Sox rally from a 4-0 deficit to beat the Los Angeles Dodgers 9-6 in Game 4 of the Series.