O'Flaherty was competing for the final spot in the Bucs bullpen, a job that still will likely go to a left-hander. The trade opens the door for Kyle Lobstein and Cory Luebke, the other leading candidates, who each had a slight edge on O'Flaherty.
"That means there's one less guy out there, one less left-hander," Pirates manager Clint Hurdle said of the bullpen competition. "Eric is in a situation with his experience -- one thing we've always tried to do is help these guys find their way back to the big leagues. And he was in a fight here. A club reached out and wanted to put him on a Major League roster right now. So we've got some guys that are still in competition."
Lobstein has pitched well this spring and already has a spot on Pittsburgh's 40-man roster, which means the club wouldn't have to remove anyone to place him on the active roster. He has a career 5.33 ERA with 59 strikeouts in 20 appearances (17 starts) since making his debut in the Majors with the Tigers in 2014.
He was 1-1 in five appearances (three starts) in Grapefruit League play before Sunday, allowing two runs, seven hits and three walks with eight strikeouts.
Lobstein said he's unsure how O'Flaherty's trade will affect him.
"I don't know," said Lobstein, traded from Detroit to Pittsburgh for cash considerations in December. "Honestly, there are a few guys in here that are in competition for a role. But at the same time, being in a new organization, it's nice getting to know guys. He was new to the organization too. … He made me feel welcome, and I tried to do the same. I guess that's a good thing, even if guys don't end up in the same place at the end of it, you still have that friendship that you build just over the short period of time."
Luebke has an opt-out clause in his contract that would allow him to leave the Pirates on Tuesday and pursue a Major League opportunity with another interested club. The 31-year-old lefty, signed to a Minor League deal with a Spring Training invitation in February, has a career 3.25 ERA with 195 strikeouts in 55 appearances (25 starts) since making his debut in the Majors with the Padres in 2010.
Luebke is 0-2 in five appearances in Grapefruit League play, allowing five runs, eight hits and one walk with four strikeouts. In Sunday night's 5-3 loss to the Orioles, he allowed two runs on three hits in one inning.
"It's just helpful for him that he's going to get the opportunity to go back to Atlanta," Luebke said of O'Flaherty. "I know it's a place he enjoys, so that will be fun for him. And as far as me, it still doesn't change anything. I've still got to go out and pitch, and whatever happens here, happens.
"I'm just excited to be playing, and whatever happens here, it's going to be a good situation. I'm in a lot better spot than I was the last three years, so it's been a good spring."
Further complicating the issue is Jared Hughes' strained left lat muscle and the competition for the last two spots in the Pirates' starting rotation.
If Hughes isn't available on Opening Day, the Pirates could have two open spots. In that scenario, Luebke and Lobstein could make the cut -- or one of the other roster spots could go to a right-hander, most likely Rob Scahill.
Andrew Astleford is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.