Yahoo!'s Jeff Passan reports the deal is for two years and $9.5 million.
Mujica, a 29-year-old righthander from Venezuela, spent the last two seasons with the St. Louis Cardinals. He had 37 saves last season before the Cardinals turned the closer role over to Trevor Rosenthal.
Mujica has been in the majors eight seasons and has a 3.75 career ERA, with a 1.134 WHIP.