Orioles manager Buck Showalter said O'Day strained his right hamstring while covering first base Wednesday in his most recent outing. He was scheduled to receive a platelet-rich-plasma injection in the muscle before Friday's game.
"He felt it a little bit," Showalter said. "… But covering first base the other night it grabbed on him and it wasn't better the next day."
O'Day is 2-1 with a 3.15 ERA in 22 games, but he owns a 6.35 ERA over his past six appearances (5 2/3 innings). After allowing just five homers in 65 1/3 innings all of last season, O'Day has already yielded five in 20 innings this season including four in his past six appearances.
The Orioles recalled right-hander Mike Wright from Triple-A Norfolk to take O'Day's roster spot. Wright was optioned Thursday, one day after suffering through his shortest start of the season, when he allowed six runs in 2 2/3 innings against the Boston Red Sox. Wright could be recalled before the mandatory 10 days an optioned player must spend in the minors because of the DL move.
Showalter said he believed O'Day would be able to return from the DL when eligible on June 18. The Orioles could not backdate the move a day because Wright returned early.
"I hope so," Showalter said. "…We hope to get him back in 15, but we'll see. I'm cautiously optimistic about that. His arm feels great."
O'Day, who signed a four-year, $31 million deal in the offseason — a club record for a reliever — has been remarkably durable during his time with the Orioles. This is his first time on the disabled list since joining the club before the 2012 season.
A decision hasn't been made as to whether Wright will return to the rotation. His demotion left the Orioles needing a starting pitcher for Monday's series opener against the Kansas City Royals. But Showalter said he would wait to see whether Wright is needed out of the bullpen over the next few games before determining Monday's starter.
"We'll see what Monday brings," Showalter said. "We're trying to get through Friday, Saturday and Sunday first. It will kind of be a moving target for the next couple days. That's why we have a TBD on Monday."
Gallardo to make next rehab start Tuesday: Right-hander Yovani Gallardo said he had some expected soreness following his first minor league rehabilitation start Thursday and is now scheduled to make a second rehab start for Triple-A Norfolk on Tuesday afternoon.
Gallardo is set to throw 75-80 pitches for the Tides after throwing 59 pitches over three innings Thursday for High-A Frederick. Gallardo allowed three runs on seven hits — several on weak contact — while striking out four and walking two.
"I feel great today," Gallardo said. "A little soreness, which is expected. Nothing crazy, nothing different. Depending on the soreness, it's more in my side or lat [muscle], which I guess is a good sign. It means I'm getting full extension to release the ball and I'm feeling good today.
"… I know it was [High-A], but yet again you're still competing against another team. You're still going out there and making adjustments throughout the game; make plays, cover first, that sort of thing. It was nice to get back out there. I was very excited to get back out there for the first time and work on the things I need to work on to get back and help these guys out."
Showalter said the Orioles hope Gallardo can return from the DL after Tuesday's start. That would put him on pace to return to the team's rotation on June 12 in Toronto.
"Hopefully five-plus innings [next start] and then we'll have a decision to make whether he needs another one or not," Showalter said. "We hope we have that and everything goes well physically between now and then. Just talking to him, you can tell by his face that he feels good about where he is."
Showalter said it's good for Gallardo to see a higher level of competition in his next rehab outing.
"This is where he needs to be," Showalter said. "He's ready for it. … I tell you, going on these rehabs to these full-season [Single-A] clubs, they're hacking, they're slashing, running on first pitch. … It's, 'Pin their ears back and we're gonna show you we're ready for the level he's pitching at.'"
Duensing debuts, settles in: There was no time for left-hander Brian Duensing to settle in before making his Orioles debut on Thursday, arriving in Baltimore in the early afternoon and pitching the ninth inning of Thursday's 12-7 win over Boston.
"Obviously, in my head, I had things going a little bit differently during the game, but I'm really glad to be here," Duensing said. "Hopefully, I can help out and take a run at this thing."
He allowed two runs on four hits in the ninth. Now that his debut is behind him, it's time to settle in with a new club after barely getting to meet his teammates before debuting.
"I feel like the new kid in school, trying to meet new friends and learn all the teachers' names and stuff like that," Duensing said. "So far, everyone here has been very welcoming. They seem like good dudes."
Around the horn: Thursday's 12-7 win over Boston marked the third time in Orioles history that the club scored at least 12 runs with all of them coming by home run, according to the Elias Sports Bureau. The Orioles also scored 12 runs — all by homer — on May 28, 1996 at the Seattle Mariners and Sept. 26, 2012 against the Toronto Blue Jays. … The Orioles will continue their weekend food and funds drive Saturday and Sunday. Nonperishable food items and monetary donations will be collected at every entrance of Camden Yards until the end of the second inning.