Cardinals' Steven Matz to be shut down with lat strain

The Cardinals will shut down starting pitcher Steven Matz for at least two weeks, president of baseball operations John Mozeliak told reporters (including Katie Woo of The Athletic). The southpaw suffered a lat strain after his latest start on Aug. 12. 

Mozeliak said Matz will be completely shut down for at least 15 days and is unlikely to throw for at least three weeks. With fewer than seven weeks to go in the regular season, Matz may be done for the year.

The Cardinals placed Matz on the 15-day IL Monday afternoon, retroactive to Aug. 13. A corresponding roster move has yet to be announced. However, he will be replaced in the rotation by fellow left-hander Zack Thompson, who is already on the 26-man roster. 

Thompson has made 17 appearances for the Cardinals this season, 16 out of the bullpen. He has a 3.96 ERA and 3.32 SIERA in 25 innings pitched. In his lone MLB start, he went four innings, allowing two hits and one earned run. He struck out eight. 

A former first-round pick, Thompson has started nine of 11 Triple-A appearances this season. He struggled to an 8.65 ERA while walking a staggering 21.8% of opposing hitters there.

Matz’s injury also ensures that Adam Wainwright will make at least one more start. The veteran was removed from his latest outing in the second inning after giving up eight runs on nine hits. Understandably, the Cardinals have given their longest-tenured player a long leash this season, but as he continues to struggle, his spot in the rotation seems less and less secure. The 41-year-old has an 8.78 ERA and a 5.67 SIERA in 15 starts.

The Cardinals have starting pitchers Connor Thomas and Drew Rom on the 40-man, and either would be a candidate to replace Wainwright in the rotation. 

Thomas, a 25-year-old left-hander, is in the midst of his third season at Triple-A and should be ready to make his MLB debut. Rom, whom the Cardinals acquired in the Jack Flaherty trade, made a strong first impression in his first start for Triple-A Memphis. The 23-year-old went five innings, giving up a single earned run and striking out 10.

Matz will be missed in the Cardinals rotation, but ultimately, the team has no reason to rush him back from the IL. Their 52-66 record has them firmly out of the postseason picture, and they have the depth to get by without him. He is under contract through 2025, and the team’s priority will be getting him back to full health for 2024.

It is certainly a good idea to take things slow with a pitcher like Matz, who has dealt with a number of injuries throughout his career. The nine-year MLB veteran was attempting to finish his first-ever season without a stint on the injured list. This isn’t his first left lat strain, either; he spent 57 days on the IL with a lat strain in 2015.

The 32-year-old got off to a rough start in 2023, posting a 5.72 ERA in his first ten starts. His strikeout rate was down, his walk rate was up, and he was missing velocity on his sinker. The Cardinals moved him to the bullpen in late May, where he almost immediately turned things around. 

In 16 innings out of the ’pen, he had a 2.81 ERA and 3.65 SIERA. His strikeout rate remained low, but he got his walks in check and regained his missing velocity.

Matz returned to the rotation on July 9 and continued to succeed. He maintained his velocity while reducing his walk rate even further, pitching to a 1.86 ERA in seven starts. 

If he cannot return in 2023, his strong performance over those final seven starts puts him in a good position to earn a spot in the Cardinals rotation next spring.