The Washington Nationals recalled left-handed pitcher John Lannan, catcher Sandy Leon and outfielder Eury Perez from Class AAA Syracuse, and activated infielder Mark DeRosa from the 15-day disabled list, the club announced Saturday. Lannan is 2-0 with a 3.46 ERA in two starts this season with the Nationals and went 9-11 with a 4.30 ERA in 24 Class AAA starts. Leon is 7-for-28 in 10 games with Washington and combined to hit .322 in the minor leagues. Perez, 22, hit .314 with 42 RBI and 51 stolen bases in the minors. DeRosa, who missed the last 25 games with an abdominal injury, is batting .152 in 66 at-bats this year.