Cabrera, 28, was in Washington's starting lineup Friday night, batting seventh and playing second base. The veteran shortstop has started 149 games at second base, most recently in 2009.
Cabrera is hitting .270 for his career, with 211 doubles and 82 home runs in 914 games, all with Cleveland.
Barrett, 26, is 3-0 with a 3.21 ERA in 40 relief appearances for Washington this season, but he has allowed seven earned runs in his last 6 2-3 innings.
His 11.5 strikeouts per nine innings are tops among all National League rookie relievers (minimum 30 innings pitched).