If the Astros are to repeat as American League champions the season after their cheating scandal, they will now have to do so without their ace, Justin Verlander.

Verlander, the reigning AL Cy Young Award winner, announced via his Instagram account that he has decided to undergo season-ending Tommy John surgery. It marked the first time in his long and accomplished career that he has needed the procedure. Verlander, who has not pitched since Opening Day in July, said he consulted with several doctors before reaching his decision.

“I was hopeful that I would be able to return to competition in 2020, however, during my simulated game unfortunately the injury worsened,” Verlander wrote on Instagram. “Obviously I’m extremely disappointed, but I will not let this slow down my aspirations for my career. I will approach this rehab the only way I know, attack and don’t look back. I’m confident that with a proper rehabilitation program and my unwavering commitment that this surgery will ultimately lengthen my career as opposed to shorten it.”

Verlander threw a simulated game at Minute Maid Park on Wednesday as a step toward determining if he could return to the mound for one start before the end of the regular season.

A forearm strain has sidelined Verlander since late July, who also missed much of Spring Training earlier this year with lat soreness and a groin injury that necessitated surgery.

Verlander will now attempt to become the tenth known pitcher to come back from Tommy John surgery after undergoing the procedure at 37 years of age or older.

Verlander enjoyed one of the best seasons of his career in 2019, winning his second career Cy Young Award, making 34 starts and going 21-6 with a 2.58 ERA, 300 strikeouts, and a 0.80 WHIP in 223 innings. He finished as runner-up in 2018. He signed a two-year, $66 million extension with the Astros last year that carries him through the 2021 season.