BOSTON -- Red Sox second baseman Dustin Pedroia has been placed on the 15-day disabled list with a strained right hamstring, manager John Farrell said Thursday, while left-fielder Hanley Ramirez is day-to-day after being struck in the left wrist by a line drive Wednesday night.
"I've never pulled a muscle before," Pedroia told reporters before Thursday's 8-6 loss to the Orioles. "It's just kind of weird, right before I hit the bag, my foot kind of slipped out and I hit the bag with my left foot. I tried to recover and stop. So I slipped, basically.
"Those are things you can't prevent. It's frustrating mentally. You work hard in the weight room in the offseason trying to prevent injury and then little things happen. It's tough but we'll get through it. Guys will come together and hold it down until I get back and then we'll go.
"Deal with it the best you can. Can't dwell on it. It's part of the game, I guess. You guys know me, I'll be back as fast as I can."
In addition, they brought up outfielder Jackie Bradley Jr., infielder Deven Marrero and relief pitcher Jonathan Aro from Triple-A Pawtucket. Bradley played right field and went 2-for-4 on Thursday. Marrero will back up Brock Holt at second base in Pedroia's absence, while Aro will take the place of Justin Masterson in the bullpen.
Masterson has been chosen to take Kelly's spot in the rotation; he will start Sunday in Tropicana Field against the Tampa Bay Rays.
Pedroia was in early Thursday morning, receiving treatment.
Farrell said he hopes that Pedroia will not require more than 15 days before he returns, but did not indicate the degree of the strain and offered no definite forecast of his return.
"He's the heart and soul of our team, in the short description of it," Farrell said. "The way he plays, what he means in the clubhouse, what he means on the field with his performance, probably having a career year to date, hopefully this is on the shorter end of the time missed.
"In other words, after the 15 days hopefully he comes back to us, but there's no projected date on his return. He'll be back as soon as he's capable."
Pedroia has been one of the few bright spots in a dismal season for the Red Sox, who are mired in last place in the AL East. Pedroia is batting .306 with 9 home runs, 33 RBIs and 34 runs scored in 69 games.
Ramirez was struck in the left wrist by a line drive hit by teammate Xander Bogaerts while headed toward second base on a hit-and-run play in the fifth inning Wednesday. Ramirez said he initially feared his wrist was broken, but X-rays and a CT scan were negative, Farrell said.
"It's really sore," Ramirez said. "I had a big bump in there, and it was really, really painful. Much less pain this morning.
"Everybody who saw it, you could see on my face it was really bad. It's going to be day to day. Treatment, ice. If I come tomorrow and I can swing the bat, I'll be in the lineup. That's what I'm here for. But it's still really painful."