Should Matthew Liberatore be the Cardinals fifth starter in 2023?

The top four of the Cardinals rotation is penciled in for opening day in Miles Mikolas, Jack Flaherty, Jordan Montgomery and Adam Wainwright, assuming the quartet can get through Spring Training or the WBC healthy. Although, the team’s fifth starter is a massive question mark. They tried multiple starters last year in the likes of Dakota Hudson, Steven Matz and Matthew Liberatore amongst others. As things currently stand Liberatore is the in-house favorite to take the staff’s fifth spot. Although with how he performed last season it is a fair ask the question of should the southpaw get the spot, or should St. Louis try to bring in a veteran starter to compete for it.

Liberatore is a former top prospect who reached as high as 37th in MLB Pipelines top 100 prospect ranking. However, he ended the 2022 season as the 80th best prospect in the game and now sits unranked in the top 100 and as the Cards 4th prospect. There’s really no way around the fact that Liberatore has been average at best since the start of the 2021 season. In 2021 he pitched to a 4.04 ERA to go along with a 4.26 FIP and 4.15 xFIP over 18 starts and 124 ⅔ innings. His K/9 was a respectable 8.88 and his BB/9 was a very strong 2.38. For a 21-year-old in AAA that’s a fine season and one you would expect him to build off of in 2022. Unfortunately, he went in the complete opposite direction. In 22 starts in AAA last season his ERA skyrocketed to 5.17 with a FIP of 4.63 and xFIP of 4.27. His K/9 improved minimally going up to 9.08 but his BB/9 jumped up to 3.21. Things got significantly worse for him in his time at the Major League level. In his 9 appearances, 7 of which were starts he pitched to a 5.49 xERA which he paired with a 4.93 xFIP, a K/9 of 7.27 and a terrible 4.67 BB/9. It does have to be kept in mind that this all occurred in a relatively small sample size but his xBA, xSLG, xWOBA and xWOBAcon were all significantly worse than league average. His struggles at the MLB level would not be nearly as concerning if he posted a solid season at the AAA level, but simply put as shown above he struggled there as well.

In terms of quality of pitches Liberatore does not push the needle enough to justify being the team’s fifth starter. Amongst pitchers to have at least 150 PAs against his four-seam spin rate was tied for 367th, his sinker was tied for 241st and his changeup was 279th. His curve was strong sitting in 42nd and his slider was tied for a respectable 89th. His curveball did feature both above average horizontal and vertical movement, although his changeup and sinker were below average in both categories. There’s no denying that Liberatore has a plus offering in his curveball, but one above average offering to go along with at best an average pitch and then three below average pitches is not enough to be a starter at the Major League level.

The big question with all of that in mind is, is there a better in-house option than Liberatore to be the Cards 5th starter? Dakota Hudson struggled mightily throughout the course of the season pitching to a 5.01 xERA whilst coming in miles below average in just about every key analytic. Steven Matz pitched to an xERA of 3.64 which ranked in the 58th percentile and was above average in a few other analytics. But Matz only pitched 48 innings due to injuries which has been the story of his career thus far. His consistent injury woes do present the question of whether or not he is better served in the ‘pen to protect his arm more.

Personally, I think Matz should be the teams fifth starter and Liberatore should start the season at the AAA level. This will help take some additional pressure off of him and allow him to try and further finetune his arsenal. Liberatore is only 23 so he has time to continue to develop but this is turning into a make-or-break season for the southpaw due to how much he regressed in 2022.