Frandsen signed a minor league contract with the Diamondbacks on Tuesday, Nick Piecoro of AZCentral.com reports. The 32-year-old was brought in to bolster the infield depth at Triple-A Reno after Danny Dorn was called up to the major league club. Frandsen hit .259/.299/.309 in 105 games (236 PA) with the Nationals last season.