Cardinals Expert Reveals Reason For This Week's Big Change

The St. Louis Cardinals opened the 2025 Major League Baseball season with a typical five-man starting rotation but now has moved to a six-man staff.

Steven Matz began the season in the bullpen and moved back to the rotation on Wednesday with a fantastic five-inning outing while allowing just one earned run and two base hits. It was a great outing and he lowered his season ERA down to 2.16.

Moving forward, the Cardinals' rotation will feature Matz along with Sonny Gray, Erick Fedde, Miles Mikolas, Andre Pallante, and Matthew Liberatore. But, why now? Why did the Cardinals start the season with the five-man rotation and choose to change it a few weeks in?

The Athletic's Katie Woo revealed why the decision was made for Matz to join the rotation on Wednesday rather than at the beginning of the season.

"A report published by Major League Baseball in December highlighted the rising amount of pitcher injuries, with concerns ranging from velocity increase, chasing movement (or 'stuff' in pitcher terms) and the emphasis of max-effort training and performance," Woo said. "Pitcher injuries have risen steadily over the last two decades, the report details, but the biggest spike has occurred in spring training and the very beginning of the regular season...

"The Cardinals would like to avoid such circumstances. Marmol and pitching coach Dusty Blake have been intentional about workload and schedule since before spring training, preferring each starter to pitch on five days’ rest rather than the traditional four. Routinely scheduled off days have facilitated that so far. St. Louis had three off days over the first 15 days of the season. Only one pitcher (Erick Fedde, against Pittsburgh) took the mound on four days’ rest. The Cardinals are now in the middle of a 26-game stretch with just one day off after the 13th game. That’s why the team pinpointed Wednesday as Matz’s first start before the season began — by switching to a six-man rotation, they can effectively ensure each starter still has enough rest days in between outings."

The Cardinals' rotation has been a real strength to begin the season and now there's a reason to believe that it could get even better with appropriate rest and the return of Matz. If all works out, Marmol and the front office is going to look like geniuses.