Seattle completed the signing of the left-hander on Tuesday. Hagadone becomes the 23rd invite to spring training by the Mariners.
Hagadone has not pitched in the majors since the middle of the 2015 season before back and elbow troubles landed him on the disabled list. He missed the entire 2016 season after undergoing surgery last February for a fractured left elbow. He spent parts of five seasons with Cleveland, appearing in 143 games and posting a 3-2 record with a 4.72 ERA.
Hagadone was originally drafted by Seattle in the 36th round of the amateur draft in 2004. Hagadone chose to attend Washington where he became a first-team all-Pac-10 selection and was drafted by the Indians with the 55th overall pick of the 2007 draft.