The Astros invited Whitley to spring training in 2019,[11] and he began the season with the Round Rock Express of the Class AAA Pacific Coast League.

[14] On March 10, 2021, it was announced that Whitley would undergo ulnar collateral ligament reconstruction, more commonly known as Tommy John surgery, and miss the 2021 season as a result.

[16] He ended the season appearing in a total of 13 games split between the FCL Astros, Single-A Fayetteville Woodpeckers, and Triple-A Sugar Land Space Cowboys, posting a cumulative 0-2 record and 6.53 ERA with 45 strikeouts in 40.0 innings pitched.

[18] After spending much of spring training battling finger inflammation, the Astros again optioned Whitley to Sugar Land to begin the 2024 season.

[20] In his first time at the Major League level, he played in three games and went 3⅓ shutout innings with five strikeouts and three walks before getting demoted on September 5.