Rea was released by the Padres on Monday.
Rea, who was designated for assignment last week, will hit the open market after passing through waivers untouched. The 28-year-old right-hander split time between Triple-A El Paso and Double-A San Antonio in 2018, posting a combined 5.76 ERA across 75 innings. Rea owns a career 4.69 ERA in 134.1 major-league frames.