Matthew Liberatore
Liberatore has had a frustrating career to this point. To get him, the Cardinals parted with Randy Arozarena, and when he became a star in Tampa, many gave up on Liberatore before he ever had a chance. The tools are there though. Liberatore throws a nasty curveball and can reach 98 from the left side. When his stuff is sharp and he maintains his velocity, he can be dominant. He pitched eight spectacular innings last season in Tampa. He recaptured that stuff against Atlanta on June 26th, firing six scoreless innings and striking out eight. He looked utterly dominant.
That comes after he got a chance to start early in the season. In his three outings, he never made it through four. Each time, his velocity dropped and he surrendered multiple runs before being lifted. On the bright side, it appears that "Libby" has significant value as a left-handed reliever. While he's put up a 5.03 ERA as a starter, that mark drops to 3.77 when pitching in relief. Opponents have recorded an OPS of .824 against "starter Liberatore." When relieving, he's held opponents to a .645 OPS. The differences are staggering. Liberatore will remain in the bullpen, though he may continue to make spot starts. He'll probably get another opportunity to start next year, but for the time being, the Cardinals need to use him where he's most effective.
Verdict: Spot starts, and that's it
Steven Matz
Steven Matz is probably the weirdest name on this list. He's under contract for another year. He's gotten countless opportunities. At times, the results have been great. At times they've been terrible, as they were earlier this year. Most often though, Matz has been unavailable. In his third year, Matz has again spent a large portion of the season on the shelf. He's out for at least another month. For the Cardinals to count on him moving forward would be ludicrous. He has shown zero ability to stay on the field. They should not be banking on him suddenly getting healthy. If Matz returns, he should be used primarily in relief. Maybe they'll let him make a spot start or two, but penciling him into the rotation is just stupid at this point.
He'll get another chance in 2025 as the Cardinals will again be pitching needy. However, until then, Matz doesn't deserve a chance to start. There are other more intriguing and healthier options, including Andre Pallante, Gordon Graceffo, Matthew Liberatore, and even Michael McGreevy. By next year, that list may include Tink Hence, Quinn Mathews, Cooper Hjerpe, and Tekoah Roby. Matz has not locked down a spot in this rotation.