Leake, who was part of Arizona's eligible player pool released earlier in the day, becomes the first MLB player to publicly opt out.
"During this global pandemic, Mike and his family had many discussions about playing this season," Leake's agent, Danny Horwits, said in a statement to ESPN's Jeff Passan. "They took countless factors into consideration, many of which are personal to him and his family. After thorough consideration, he has chosen to opt out of playing in 2020.
"This was not an easy decision for Mike. He wishes the best of luck and health for his Diamondback teammates this season and he's looking forward to 2021."
As he's not considered a player at high risk of contracting COVID-19, Leake will not be paid this year. By opting out, Leake is walking away from a salary of approximately $5.6 million over the 60-game season, according to Joel Sherman of the New York Post. Had it been a normal year, he would have earned $16 million in 2020, the final guaranteed year of his contract.
Leake's contract contains a mutual option for 2021 valued at $18 million, with a $5-million buyout. That option remains active despite the season being shortened, according to Jon Heyman of MLB Network.
Arizona acquired Leake, an Arizona State alumnus, from the Seattle Mariners last July. He posted a 4.29 ERA, 5.19 FIP, and 1.29 WHIP across 197 total innings in 2019 and allowed an MLB-high 41 home runs. He also won the AL Gold Glove at his position despite switching leagues midseason.
The 32-year-old owns a career 105-98 record with a 4.05 ERA, 1.28 WHIP, and 1,231 strikeouts across 10 major-league seasons with the D-Backs, Mariners, Cincinnati Reds, San Francisco Giants, and St. Louis Cardinals.
Players like Leake who are not high-risk but choose to opt out will not be allowed to return later in the season, per Jayson Stark of The Athletic.