Olivo stayed in the game after Encarnacion's fifth-inning foul tip bounced up and caught him in the jaw, but was taken out an inning later after striking out in the bottom of that frame.
"He got his bell rung pretty good on that foul ball and he just didn't look right when he was swinging the next inning," manager Eric Wedge said. "I asked him before he went up there and he said he felt OK, but then he felt like he was feeling the effects of that afterward."
Wedge said the 32-year-old catcher was being examined by the medical staff postgame, with a further update expected on Wednesday.
Olivo hit a solo home run in the second inning, his team-leading 15th of the season, and his first since July 24. He also drew a walk in the third, ending an even longer draught as he hadn't earned a base on balls since June 26.
He's now hitting .217 with a team-high 50 RBIs, as well as the 15 home runs.