Severino has been placed on the injured list due to an oblique strain, and the Athletics' third-ranked prospect, Morales, will make his start.

The Athletics' rotation is about to become even more inexperienced. Ahead of today's game at Camden Yards against the Orioles, their starting pitching staff, which already had three rookies, will lose their most experienced member, Luis Severino. He has been placed on the 15-day injured list due to a left oblique strain (retroactive to Thursday). In tomorrow's series finale, the Athletics' farm system's third-ranked prospect (79th overall in the MLB rookie rankings), Luis Morales, will replace Severino, marking his first career start in the majors and his second appearance overall.

According to Athletics manager Mark Kotsay, Severino has been pitching while injured for a while. However, after his most recent start against the Nationals on Wednesday, the discomfort he felt was more significant than usual. Today, Severino underwent an MRI, which confirmed the oblique strain.

“He has been pitching through the injury and handling it well,” Kotsay said. “But he wasn’t able to bounce back after his last start. Yesterday was the day we had to make a decision. … When we return home on Monday, we’ll do more imaging. For now, it’s a left oblique strain.”

The Athletics hope Severino can return to the mound this season, but losing him, no matter how long, is undoubtedly a heavy blow. As of today, the Athletics' starting pitchers have allowed nine earned runs or fewer in 16 games, with a collective ERA of just 2.63 during that span.

Severino has been a key part of this recent success. Although he started the season disappointingly as the team's opening day starter, Severino has improved over the past month. In his last five starts, he has gone 4-1 over 27.2 innings with an ERA of 2.93, recording 30 strikeouts and 8 walks.

“He really found his groove after the All-Star break and in the few starts before that,” Kotsay said. “He was pitching very well and going deep into games. We won most of his starts, which provided a lot of momentum for the entire team. Now, we have to move in a different direction.”

That direction is the ongoing youth movement. Morales will join fellow rookies Jacob Lopez, J.T. Ginn, and Jack Perkins in the rotation, with Perkins making his second career start today.

The 22-year-old Morales quickly climbed the Athletics' system after signing from Cuba in 2023, showcasing his electric pitching. He made his major league debut on August 2 at Sutter Health Park, where he allowed one run over two innings as a reliever, featuring a fastball topping out at 97.8 mph, along with a top-notch cutter and an improving changeup.

It remains unclear if Morales' transition to the starting rotation will be permanent. This season, he has pitched a total of 91.1 innings in both the minors and majors, marking the most innings he has thrown in a season as a professional, which is part of the reason for his shift from long relief to starting.

Morales will be on a pitch limit for his start tomorrow. After that, the Athletics will decide how to handle this rotation spot.

“We’ll take it day by day,” Kotsay said. “We’ll monitor him. He started the season as a starter and then transitioned to primarily a three-inning reliever. We’ll evaluate him now and see how he responds to this opportunity.”