Arizona Diamondbacks pitcher Mike Leake is the first MLB player to officially opt out of the 2020 season ... with his agent confirming the news Monday morning.

The 32-year-old -- who nearly had a perfect game last season -- released a statement via Danny Horwits ... saying he will not be participating in the league's shortened 60-game plan next month.

"During this global pandemic, Mike and his family had many discussions about playing this season," the agent told ESPN's Jeff Passan.

"They took countless factors into consideration, many of which are personal to him and his family."

Horwits continued ... "After thorough consideration, he has chosen to opt out of playing in 2020. This was not an easy decision for Mike."

The agent did not reveal the reason Leake decided to sit out the season ... but more players are expected to follow leading up to next month's training camp.

"He wishes the best of luck and health for his Diamondback teammates this season and he's looking forward to 2021."

Leake's been a solid pitcher in the league since he made his debut in 2010 ... and won 12 games for the Mariners and Diamondbacks last year.