Phillips was kneed in the head Wednesday by Aramis Ramirez in the third inning of the Reds' 8-4 loss to the Milwaukee Brewers on a caught-stealing play. He stayed in the game until the fifth and then was removed.
Phillips hit in the batting cage early Thursday afternoon.
"I feel OK," he said after the session in the cage. "I'm just going to go on the field (during batting practice) and see what happens. That's the only thing I can really say. ... Hopefully, I can help the team out."
Manager Dusty Baker wanted Phillips to feel better than OK.
"The trainer said when he runs around and gets the blood flowing, he could feel better or he could feel the same," Baker said. "If he feels the same, he's not playing."
After the on-field session, Phillips was taken out of the lineup.
Baker didn't want to risk playing him.
"Especially in this twilight with these hard throwers," Baker said. "You lose any kind of vision, you could get hit upside the head by (a) 95 (mph pitch)."