The Mariners signed Milner to a minor-league contract Monday and selected his contract from Triple-A Tacoma.
Milner was released by the Cubs on Sunday but has quickly landed on his feet. The southpaw reliever hasn't pitched in the majors since undergoing an appendectomy in late June, but he's healthy now and will give manager Dan Wilson another lefty reliever. Milner has logged a 3.53 ERA, 1.21 WHIP and an 18:9 K:BB over 35.2 innings in the big leagues this season.