Forsythe, normally a second baseman, has been filling in at third for the injured Justin Turner.
Before Saturday's game, Turner, who is out with a fractured left wrist, played catch while wearing a glove on his right hand as he assisted with infield practice. Roberts said there is no timetable for Turner's return.
Forsythe was 0-for-2 at the plate before he left. The Diamondbacks won 9-1 to stretch their win streak over the Dodgers to 11 straight regular-season games dating to August 2017.
The Associated Press contributed to this report.