Utley was scratched from the lineup for Philadelphia's 7-3 win against the Miami Marlins on Tuesday night after feeling discomfort in his ribcage during batting practice. He was not in the lineup for Wednesday night's series finale.
Utley hopes to avoid a trip to the disabled list.
"I think we caught it early enough, but it's hard to tell until we have some type of evaluation on it," he said.
Utley is hitting .272 with seven homers and 25 RBIs. He was sidelined with knee problems for significant stretches the past two seasons.
"It definitely scared me a little bit," Utley said. "I took my first swing in BP and felt something. On the second swing, I felt it again. Third swing, felt it again. After the fourth swing, I realized something wasn't right."