"The pitch hit in the left lat area, left rib cage. It continued to swell and tighten up," Red Sox manager John Farrell said, per ESPN.com. "He was losing a lot of range of motion with the left arm, so we had to get him off his feet. We'll have a better read once he goes through the exam here at the local hospital."
Astros pitcher James Hoyt hit Pedroia, 33, in the top of the seventh inning. He briefly stayed in the game to run the bases but was later taken out for Pablo Sandoval, who went to third base while Josh Rutledge moved over to second.
Ferrell did not reveal the result of the X-rays.
Pedroia entered Sunday with six multihit games in his last eight, instantly returning to form after missing time with a sprained wrist. He has already missed 14 games in 2017 after sitting out only eight a year ago.
When he's been in the lineup, Pedroia has remained effective—albeit not hitting with as much power as a year ago. He's hitting .296/.368/.376 with two home runs and 25 RBI.