Billy McKinney will bat eighth and play right field in the opener of a three-game series.
Betts left Friday’s game in the sixth due to right hip discomfort. He played Saturday and then sat out Sunday.
Manager Dave Roberts said before Tuesday’s game an IL stint “is very probable” for Betts.
Betts is batting .277 with 17 home runs and 44 RBIs in 87 games for the defending World Series champions.
Dodgers third baseman Justin Turner also is expected to miss the Phillies’ series with left groin pain.
“I don’t see him coming back any sooner than Friday in New York,” Roberts said.
The Associated Press contributed to this report.