"My back tightened up on me," Dietrich said. "I guess back spasm or whatever. I got treatment all day yesterday. I'm available off the bench. Hopefully I'll be back in there [Monday]."
Manager Mike Redmond said he didn't plan on using Dietrich in the series finale at Philadelphia. The second baseman would only play in case of an extreme emergency. Jeff Baker started in place of Dietrich.
Dietrich felt some discomfort on Friday night while making a relay throw in the fifth inning on Jimmy Rollins' triple.
"I threw it, and my back started feeling a little weird," Dietrich said. "I woke up, it was a little tight. We just erred on the side of caution. I got a lot of treatment and [I'm] feeling a lot better today."
Dietrich has been starting at second base against right-handed pitchers, while Baker has been getting the call against lefties. The left-handed-hitting Dietrich is batting .313 with two home runs.
"He's better today," manager Mike Redmond said Sunday. "But his status is the same as yesterday. He's not playing today."