Phillips, who has had a lingering left hamstring injury, sat Friday because of cold weather and wet conditions.
Manager Dusty Baker said his original plan was to play Phillips on Friday and Saturday and sit him for Sunday's series finale -- which, including Monday's off-day -- would have given Phillips two consecutive days off to receive treatment.
Baker said he now plans on starting Phillips on Sunday, but Baker will monitor him and take him out of the game if the Reds happen to get a big lead.
Baker's said his biggest concern about Phillips sitting is the second baseman losing his stroke. Phillips went 2-for-5 with his first home run Thursday in St. Louis after beginning the season hitting .200 (5-for-25).
"You just find your stroke and you take too many days off, you'll lose it like that and then you'll never have it," Baker said. "His timing was off, so hopefully he'll be able to swing like he did [in St. Louis]."