I found my answer. Per Jake Kaplan, Whitley was optioned to the minors during spring training, so he’s on the minor-league IL, which makes him ineligible to be on the MLB 60-day IL.
To free up the roster spot, they’d first have to recall him from the minors to the majors before placing him on the 60-day IL. That’d start the service time clock and Whitley would accrue a major league salary. No way the Astros do that unless they are really desperate.
All 9 of Hartman’s appearances in AAA were starts. Has it been said if he is moving into Urquidy’s rotation spot or going to the bullpen with Javier talking Urquidy’s spot???