The Rangers released Cabrera on Sunday.
Cabrera hit .229 with five home runs and 21 RBIs in 49 games with the Nationals in 2014.
Cabrera is a career. 267 hitter with 174 home runs and 756 RBIs since debuting with the Cleveland Indians in 2007. He is a two-time All-Star selection.
Washington entered play Monday with a 58-53 record. The Nationals are tied with the rival Philadelphia Phillies for the National League's second Wild Card spot.