As a precaution, Gwynn had an MRI on Friday, which showed a jammed shoulder.
However, the MRI hasn't officially been read by Dr. Neal ElAttrache, who will review it later on Friday night.
"Everything looks pretty good, but we won't know for sure until Dr. ElAttrache reads it," Dodgers head trainer Stan Conte said. "He is going to be down for a few days for sure. We knew that after he did it."
Gwynn originally injured the shoulder after a steal of second in Los Angeles' series against the Nationals, and felt something again after sliding into home plate on Wednesday.
The Dodgers outfielder didn't play in Thursday's series opener against the Pirates.
"It is an aggravation of an almost healed injury," Conte said. "He progressed well last time, so we'll see what happens this time."