Left-hander James Paxton is returning to the Seattle Mariners after an injury-filled second season with the New York Yankees.

Paxton and the Mariners are in agreement on a one-year, $8.5 million deal, sources told ESPN’s Jeff Passan on Saturday. The contract includes reachable bonuses that could take its value up to $10 million, sources said.

Paxton, 32, was 41-26 with a 3.42 ERA for the Mariners from 2013 to 2018, striking out 617 and walking 168 in 582⅓ innings. He was traded to the Yankees in November 2018 for a top prospect, left-hander Justus Sheffield, along with outfielder Dom Thompson-Williams and right-hander Erik Swanson.

The Mariners held out hope when Paxton was traded there could be a reunion in the future with the native of nearby Ladner, British Columbia.

Paxton struggled in the first half of his first season in New York, rediscovered his breaking ball in the second half and went 15-6 with a 3.82 ERA. He won a career-best 10 straight starts before leaving his final regular-season start after one inning on Sept. 27, 2019.

The Yankees said he had a tight left glute muscle, and he returned to go 1-0 with a 3.46 ERA in three postseason starts, allowing five runs in 13 innings. But he needed surgery in February 2020, when Dr. Andrew Dossett in Dallas performed a microscopic lumbar discectomy to repair a herniated disk and remove a peridiscal cyst.

Paxton was able to start the season on time when the COVID-19 pandemic caused a delay until late July, but he went just 2-3 with a 6.64 ERA in five starts. He did not pitch after Aug. 20 after suffering what the Yankees said was a low-grade strain in his left forearm flexor.

The Yankees let Paxton, Masahiro Tanaka and J.A. Happ leave as free agents, replacing them with Corey Kluber and Jameson Taillon.

Paxton was a fan favorite during his first stint in Seattle. His best seasons came in 2017 and 2018, when he went a combined 23-11 with a 3.40 ERA and threw the only no-hitter of his career in May 2018 against the Toronto Blue Jays.

Paxton figures to join a rotation initially projected to include Marco Gonzales, Yusei Kikuchi, Sheffield and Justin Dunn. Coming off a third-place finish in the American League West at 27-33, Seattle previously added free-agent right-hander Chris Flexen, agreeing to a two-year, $4.75 million contract.

Seattle is expected to use a six-man rotation, which would likely to take away about five starts from each pitcher in the rotation. The addition of Paxton will likely move Nick Margevicius into a bullpen role.

The Associated Press contributed to this report.