SEATTLE -- The Mariners declined a $5 million team option to renew veteran left-hander Wade LeBlanc’s contract for 2020 on Thursday, leaving the club with just two of its initial five starters returning from last season’s rotation.

LeBlanc will be given a $450,000 buyout and now becomes a free agent, able to sign with any Major League team once that process begins on Monday.

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LeBlanc joins five other Mariners who became free agents on Thursday, the day after the end of the World Series that saw the Nationals knock off the Astros in Game 7 in Houston.

Right-hander Félix Hernández is the most prominent of Seattle’s free-agent group as he hits the open market for the first time after 15 seasons, and he is joined by left-hander Tommy Milone and right-hander Arodys Vizcaíno. Infielder Ryon Healy and outfielder Keon Broxton also will become free agents after declining outright assignments to Triple-A Tacoma earlier this week.

LeBlanc and Hernández both opened the season in Seattle’s rotation, along with Mike Leake, who was traded to the D-backs on July 31. Milone also started six games and was a “bulk reliever” following an opener in 17 other games. Their departures leave Marco Gonzales and Yusei Kikuchi as the primary returning starters, with rookie Justus Sheffield also due back after starting seven games at the end of the season.

Rookie Justin Dunn, who started four games in September, is another rotation candidate for 2020, but general manager Jerry Dipoto likely will sign a veteran free-agent starter or two for depth purposes this winter.

LeBlanc’s departure isn’t much of a surprise as the 35-year-old went 6-7 with a 5.71 ERA in 26 outings (eight starts). Like Milone, LeBlanc was used extensively in a “bulk relief” role once the Mariners began experimenting with the opener strategy, and by September he was moved strictly to a little-used long-relief role as Sheffield was worked into the rotation.

LeBlanc went 9-5 with a 3.72 ERA in 32 games (27 starts) in 2018 and signed a midseason contract extension that could have earned him as much as $31.3 million over four seasons, including incentive bonuses. But his $5 million a year base options for '20-22 were only guaranteed if he pitched 160 innings the previous season, and an early-season injury and eventual bullpen usage left him at just 121 1/3 frames this year.

LeBlanc earned a career-high $3.25 million in 2019, including $500,000 in performance bonuses for innings pitched. He initially signed with Seattle for $650,000 prior to the start of the '18 regular season after requesting his release from the Yankees, and he quickly moved into the rotation and pitched a career-high 162 innings that year.

LeBlanc is 45-47 with a 4.46 ERA in 234 games (114 starts) over 11 seasons in the Majors, and he has pitched for seven organizations, as well as spending 2015 in Japan.