The 35-year-old was activated April 9 after starting the season on the injured list with inflammation in the knee but left Wednesday night's game against the New York Yankees in the second inning. He was examined Thursday, when Boston put him back on the IL.
"More kind of scared me than anything," Pedroia said before Friday's 6-4 win at Tampa Bay. "I was nervous, obviously, to feel that. We're just going to let it calm down for a few days and then it should be all right. I hadn't had any issues up until this point."
Pedroia said he felt a pop as he went to rotate on a swing.
"Sometimes the batter's box are a little tacky and things like that," Pedroia said. "The brace I wear is strapped around, so it kind of like torqued, and my knee didn't."
Red Sox manager Alex Cora thought the injury could be serious.
"The way he reacted that day, I was like, 'Oh, this is it right here,'" Cora said. "I was thinking the worst. I'm relieved. We got some positive news. Now it's just a matter to see how he reacts during the week. When he's ready, he's ready."
Pedroia has appeared in six games with Boston, making four starts at second base and two as a designated hitter. He is 2-for-20 with a walk, one RBI and one run scored. He did not need an MRI.
"I've been through a lot," said Pedroia, who will use a different type of brace when he returns. "It's fun being out there playing. It was just a weird, freak thing."
Boston made several other moves Friday, placing infielder Eduardo Nunez on the 10-day injured list with a mid-back strain, retroactive to Thursday, and designating right-handed pitcher Erasmo Ramirez for assignment.
"It's been going on for a few days," Cora said of Nunez's back issues. "He's been fighting it. It gets to the point that, let's stay away from him, get him better."
Boston also traded catcher Blake Swihart and international amateur signing bonus pool space to the Arizona Diamondbacks in exchange for minor league outfielder Marcus Wilson.
Infielders Tzu-Wei Lin and Michael Chavis were recalled from Triple-A Pawtucket. Cora said Lin likely will get the majority of the time at second base with Pedroia out.
Chavis, 23, is on an active major league roster for the first time. He was the 26th overall pick in the 2014 amateur draft.
"We'll find a way to get Michael at-bats," Cora said. "I'm happy for the kid that he's a big leaguer. Hopefully he can make an impact."
The Associated Press contributed to this report.