He caught the first six innings and went 1-for-3 before Kelly Shoppach replaced him.
"I felt OK before the game. It kept kind of creeping in and then just kept getting worse and worse and then it didn't feel like it was going to get any better whatsoever," Saltalamacchia said. "It wasn't the right time to go out there when we're trying to win the game feeling like I was."
Saltalamacchia was on an IV as recently as Saturday after being dehydrated. He entered Saturday's game in the ninth inning as a pinch-hitter, crushing a two-run walk-off home run on the second pitch he saw to beat the Rays. Since then, he has started the last three games for Boston.
"It's just a little illness. It wasn't getting any better, just kept getting worse, but no dehydration or anything of that nature," Saltalamacchia said. "It's just something that came up and I should be good to go tomorrow."
He is not the first player on the team to feel ill this week.
"There's something going around," said manager Bobby Valentine. "[Will] Middlebrooks in the middle of the game yesterday was having issues. Just maybe that stuff going around."
Saltalamacchia homered over the Green Monster in the series opener against Detroit on Monday. He has four homers in his last nine games and is hitting .274 with 22 RBIs in 39 games this season.