Doumit, tied for second on the team in home runs with eight and RBIs with 32, left Wednesday night's game against the Milwaukee Brewers in the fourth inning because he felt lightheaded and nauseous. Doumit did not play Tuesday after taking a foul tip off his mask during a game Monday.
Jaramillo was optioned to Indianapolis at the All-star break after hitting .164 in 24 games with Pittsburgh. He went 6 for 17 with a double and four RBIs in five games with Indianapolis.
Manager John Russell said Jaramillo and Erik Kratz would split the catching duties.