Garrett cleared waivers and refused an outright assignment to Triple-A Rochester on Friday, making him a free agent, Bobby Blanco of MASNSports.com reports.
The 30-year-old was designated for assignment by the Nationals in December to clear space on the 40-man roster for Jeter Downs. Garrett played in just seven MLB games last year and spent most of the campaign with Rochester, where he had a 3.04 ERA, 1.23 WHIP and 53:18 K:BB in 47.1 innings.