KANSAS CITY -- Left-hander Danny Duffy, his Major League return behind him, was optioned back to the Royals' Triple-A Omaha club on Thursday, at least for the time being.
To take his spot, left-handed reliever Francisley Bueno's contract was purchased from Omaha and he was put back on the Royals' 40-man roster. To make room, catcher Adam Moore was put on unconditional release waivers.
"Another left-handed arm. He's been doing well down in Omaha, been closing some games out. We wanted some more left-handed protection." manager Ned Yost said.
Bueno joins Tim Collins to give the bullpen a second lefty. Will Smith, a left-hander who was returned to Omaha on Wednesday, has to remain in the Minors for 10 days.
That would be the case for Duffy as well, except he could return before that as the 26th man permitted for a doubleheader, which the Royals happen to have a week from Friday at Detroit. Although Yost is not revealing any plans in advance, that's certainly an option.
Meanwhile, Duffy could make a start for Omaha with limited pitches between now and then.
"I know they have confidence in my stuff. They wouldn't have brought me here if they didn't," Duffy said. "I'm really lucky and blessed to say I was part of this team in one way or another."
In his return from Tommy John surgery on Wednesday night, Duffy started a 5-2 victory over the Twins and went 3 2/3 innings, giving up two runs.
"You just wanted him to get out and get it over with. It's like your first Major League start. I wanted to get past it because when you go through what he's gone through and what [Felipe] Paulino has gone through, that's a big start for you," Yost said.
"You come back, you've battled your way back. You know there's going to be a lot of emotion, you know all the hard work you've put in for the last 14, 15 months -- and this is why. You get the opportunity to go back out and pitch a Major League game."
Duffy made 31 pitches in the first inning and exited after 93 pitches.
"His stuff was great, his curveball was off, his command was off, but a lot of that had to do with overthrowing and being hyped up in the moment of everything that was involved with it," Yost said.
Bueno, 32, had a 3-3 record, a 2.93 ERA and one save in 31 games for Omaha. In his last six outings, his ERA was 0.87. Signed as a free agent prior to the 2012 season, Bueno relieved in 18 games for Kansas City last year, with a 1-1 record and 1.56 ERA.
Moore, 29, is out for the season after undergoing surgery because of a torn groin adductor. He was with the Royals while Salvador Perez was on bereavement leave this year and played five games, going 3-for-10. For Omaha, Moore batted .191 with eight homers and 23 RBIs in 41 games before being injured on July 19.
Holland joins Royals' elite with 30th save
KANSAS CITY -- Closer Greg Holland joined esteemed company on Wednesday night, becoming just the fourth pitcher in franchise history to record 30 saves in a season. The others were Joakim Soria, Jeff Montgomery and Dan Quisenberry.
"I don't really concern myself with it that much, to be honest," Holland said. "It's nice to be in good company with other good players, other than that you have to try to stay in the moment and enjoy it and try to go win a ballgame."
Holland has 23 consecutive saves and a 0.96 ERA in that span and allowed just three earned runs in his last 28 innings pitched with 44 strikeouts.
He and the rest of the bullpen have been vital to the team's 15-4 run since the All-Star break, boasting an American League-best 2.80 ERA during that span.
"We feel really comfortable when giving them a lead and anytime we get insurance runs in the late innings with the bullpen coming in, it's a good feeling," first baseman Eric Hosmer said. "The game plan is just to get it to Holland and the guys have been getting it to him and doing a phenomenal job getting it to him. As a unit, they're doing a great job."
They are also the most rested bullpen in the league, working 308 1/3 innings. A year ago, the Royals' bullpen had the second-most innings pitched in the league.
With two extra-innings battles in New York and a short start by Danny Duffy on Wednesday, they're benefiting from the extra rest.
"All year, we haven't been used as much as we have in the past, just because of our starting pitching, so when it comes time for games like that [in New York] or even [Wednesday night] picking up the amount of innings we did, we're ready for that as opposed to last year when it was questionable who was going to be able to pitch that day," left-handed reliever Tim Collins said. "Sometimes we're going to have to pick up innings like that but we've been well-rested all year."
Paulino continues rehab in Omaha
KANSAS CITY -- Royals right-hander Felipe Paulino pitched three innings for Triple-A Omaha on Thursday night on a rehabilitation assignment.
Paulino, who is recovering from July 2012 Tommy John surgery, allowed four runs (two earned) on five hits and a walk with four strikeouts in Omaha's 6-4 loss to Sacramento. He threw 62 pitches and 46 were strikes.
Paulino started a rehabilitation assignment on June 11, when he pitched five scoreless innings with two hits, six strikeouts and two walks for Double-A Northwest Arkansas. He returned to Kansas City with lower back stiffness on June 17, and after also being treated for shoulder stiffness, restarted his assignment on Saturday, allowing two runs on three hits and two walks with two strikeouts in three innings of Northwest Arkansas' 6-5 loss to Tulsa.
Perez working way back from concussion
KANSAS CITY -- Royals catcher Salvador Perez is quickly progressing through concussion testing and still feeling fine.
After a 15-minute bike workout on Wednesday, he took a supervised jog and underwent more physical testing on Thursday.
"I did my bike workout yesterday and felt great," Perez said. "I felt nothing in my head. I still feel better every day."
Perez is eligible to return on Sunday, but manager Ned Yost said the club will take its time and make sure Perez is completely healthy before bringing him back.
"Sal is an extremely valuable component to our team, and we can't take any chances of anything like that," Yost said. "We need to make sure we do it right. Of course, like anything it's a healing process and it was a very slight concussion so the healing process is going to be much faster and we are still hoping to stay in the seven-day realm."
Tickets available for Red Sox series
KANSAS CITY -- The Royals still have plenty of tickets available for their four-game series against the Red Sox.
The Red Sox lead the American League East with a 70-46 record but the Royals hold a 2-1 lead in the season series. Going into Thursday night's game the Royals have gone 15-4 since the All-Star break.
Dick Kaegel is a reporter for MLB.com. Kathleen Gier is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.