Merrifield had two homers and a career-high six RBI, Bailey worked into the eighth inning with 121 pitches and the Royals beat the Seattle Mariners 9-0.
The Royals jumped on struggling starter Yusei Kikuchi to get their third straight win. Merrifield drove a three-run homer against Kikuchi (3-5) in the fourth and added a two-run shot against Jesse Biddle in the eighth. Jorge Soler also homered for the Royals, and rookie Nicky Lopez had three hits.
That allowed Bailey to shift his focus toward covering as many innings as possible. He struck out six and gave Kansas City's bullpen a breather.
"Getting the run support and the energy from the guys really helped picked me up and I knew I had to sharpen up, try to have some quick innings," Bailey said. "Once we started scoring runs, my focus was really: go out there, have some quick innings, get the guys back in here, let them keep swinging."
And swing they did, right from the start. The Royals started the game with three consecutive singles, taking a 2-0 lead on Alex Gordon's two-run single. Soler added his 20th home run in the third to make it 3-0 and Bailey started rolling around the time Merrifield hit his first home run that made it 6-0 in the fourth.
After stranding two runners in each of the first three innings, Bailey retired 14 of the next 15 he faced. As the game reached the eighth, Bailey was asked if he could start the inning. His response? "Absolutely."
"He executed his pitches, it's as simple as that," Royals manager Ned Yost said. "He does a great job of pitching. He's a big league veteran guy. He's got two no-hitters under his belt. He knows how to pitch, how to execute pitches. On days where he's grinding, he knows how to make pitches when he needs to."
Bailey (6-6) allowed just one baserunner past second in 7 2/3 innings and struck out six with just two walks.
Kikuchi allowed six runs in five innings. The Japanese rookie has had an unsettling June after a fairly positive start to his major league career. He's 0-4 in five starts since May 25 and has allowed eight home runs during that stretch. Merrifield, who also had a two-run home run in the eighth inning and a sac fly, said Kikuchi got himself into trouble by falling behind in the count at key times.
"We knew this was going to be a process," Seattle manager Scott Servais said of Kikuchi's conversion from Japanese baseball.
Royals: Adalberto Mondesi left the game with right groin tightness. Yost said he will be held out of Wednesday's series finale with the Mariners.
Mariners: Felix Hernandez was scheduled Tuesday to have an MRI on his right shoulder. The right-hander left his rehab assignment at Triple-A Tacoma on Friday due to fatigue and was scheduled for the scan of his right lat and the back of his shoulder after a visit with doctors Monday. Servais said the development is not good news for the 33-year-old, who has been out since May 12. "It's concerning enough to take new images of that (injured area) and not guess," Servais said.
Mitch Haniger said he is no longer in pain while walking after rupturing a testicle during a game this month. The All-Star right-fielder hopes to restart more strenuous activities like running this weekend or next week. He's done some light arm and balance work while the Mariners were on the road, then rejoined his teammates in the clubhouse for the Kansas City series.
"The first couple of days the pain is too much and you can't really move, so you don't really have any options," Haniger said. "But right now I feel like I'm walking around and there's no pain, so I'm really trying to get things going but really not make it worse."
Servais said the plan is to "be really cautious, really smart" with Haniger's return.
Royals: RHP Brad Keller (3-8, 3.97 ERA) tries to stop a run of seven losses in eight appearances since April 22.
Mariners: LHP Marco Gonzales (7-6, 4.50 ERA) is looking for his third straight win since stopping a six-game losing streak.
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