"It's his forearm flexor extensor," manager Bruce Bochy said during Tuesday's morning workout. "He's in there tomorrow."
In 11 Cactus League games, Schierholtz is hitting .258 (8-for-31) with a pair of doubles and four RBIs. He last played Saturday.
"I hurt it about a week ago," Schierholtz said. "It just started getting sore. It wasn't really anything in particular. I think it's a light strain. It's just something that swinging every day, it's gotten a little bit worse, so [I took] a couple days off to calm it down. The off-day [Monday] helped a lot with today [off, too]."
Schierholtz is fine to throw, but the nature of the forearm strain affects his swing.
"It's annoying," Schierholtz said. "I'm not really happy about it, but then again, I don't want to play at 50 percent or do something to it. Otherwise, I feel good, but I need to be healthy to be playing. It's just one of the minor things that nags unless you give it a little rest. If it was the season, it would probably be different."
Gregor Blanco took Schierholtz's place in the lineup. Blanco entered Tuesday hitting .444 (16-for-36) with two doubles and three RBIs in 13 spring games.
Owen Perkins is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.