The team added Jamie Burke from Triple-A Syracuse on Saturday.
The 31-year-old Maldonado, summoned from Syracuse when Ivan Rodriguez was placed on the DL on May 24, was hitting 3 for 11 with a home run and three RBI in four games.
Burke was hitting .278 for Syracuse. The 38-year-old is a career .277 hitter in seven major league seasons with Anaheim, the Chicago White Sox, Seattle and Washington.
To create a spot on the 40-man roster for Burke, the Nationals released catcher Chris Coste. The 37-year-old Coste was claimed off waivers from the New York Mets on March 29 and has been on the disabled list all season.