A baseball pitcher on the mound throwing the ball to the plate.
Padres starter Matt Waldron (61) delivers a pitch during the third inning of a game against the Cleveland Guardians on July 19, 2024, at Progressive Field in Cleveland. (Photo by Frank Jansky/Icon Sportswire)

Padres right-hander Matt Waldron is nursing a mild oblique strain he suffered while warming up before entering a spring training game.

Waldron was scheduled Friday to come in and throw against the Texas Rangers. He could miss the start of the season.

“Obliques take a while,” manager Mike Shildt said on MLB.com. “We’ll re-evaluate it, but he’s going to need some rest for some period of time, which will be determined.”

Waldron, 28, went 7-11 with a 4.91 ERA in 27 appearances, all but one of them starts, for the Padres last season.

Michael King, Dylan Cease, Yu Darvish and Nick Pivetta have locked up spots in the starting rotation. With Waldron sidelined, two right-handers, Stephen Kolek and Randy Vásquez are being considered for the final rotation slot, along with lefty Kyle Hart.

Meanwhile, the team’s Spring Breakout game took place Friday, featuring two of the club’s top prospects, catcher Ethan Salas and shortstop Leo De Vries, both 18. Salas had two hits and De Vries. had an impressive double.

Against a more experienced Oakland A’s squad, the young Padres fell 5-2, but Salas saw the bright side.

“It was fun,” he told MLB.com. “It was good competition. Put up a good game, started to get hot toward the end.”