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5/11/2014 10:04 P.M. ET

Duffy to start Saturday for ailing Chen

SEATTLE -- It's settled now. Danny Duffy, not Bruce Chen, will start Saturday's game for the Royals against the Orioles at Kauffman Stadium.

Chen is making progress in his recovery from a bulging disk in his back but he's not far enough along to return to the rotation by the May 17 date that manager Ned Yost had hoped.

Back in Kansas City, Chen is undergoing treatment and playing catch but he's not yet gone out to pitch on a Minor League rehabilitation assignment.

So Duffy, who was passed over in the latest turn of the rotation because of last Monday's open date, will make his third start as Chen's replacement.

Duffy went four innings in his first start, giving up one run on two hits to the Tigers, and then went six innings at San Diego, again with one run on two hits. Both games turned out to be losses but Duffy's showings were encouraging.

"He's been doing fine," Yost said. "Our pitching's been fine, we just need to get the offense going. [Yordano] Ventura gives up three runs and it felt like it was 19."

That was a reference to Saturday night's 3-1 loss when the Royals came up with only four hits.

Pink bats contribute to rosy afternoon

SEATTLE -- Let's hear it for the Royals' pink people.

The players who used pink bats excelled in a 9-7 victory over the Mariners on Sunday. They were part of the pink accent to games throughout the country as Major League Baseball promoted awareness of the fight against breast cancer.

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The five in the lineup who used pink bats for the Royals -- Eric Hosmer, Danny Valencia, Alex Gordon, Alcides Escobar and Brett Hayes -- combined to go 9-for-21, or .429.

"I've never had success with a pink bat until today," said Gordon, who went 3-for-4 with a walk. "So mother was looking out for us."

Escobar used his pink bat to blast his first bases-loaded home run.

"The best part is I hit my first grand slam on Mother's Day," he said.

The four players that used normal bats -- Nori Aoki, Billy Butler, Lorenzo Cain and Johnny Giavotella -- were a combined 3-for-17, .176. However, Giavotella provided the game-deciding, three-run homer.

So no one could complain. It was all for a good cause on a winning afternoon.

Valencia batting cleanup while Perez rests

SEATTLE -- Because he was giving sore-legged Salvador Perez a break Sunday, Royals manager Ned Yost needed to fill the fourth spot in the batting order with somebody else against Mariners left-hander Roenis Elias.

Right-handed designated hitter Billy Butler was slotted third behind lefties Nori Aoki and Eric Hosmer and Yost didn't want to move lefty Alex Gordon up from his usual fifth spot.

"I didn't want to bunch a bunch of lefties together," Yost said. "I could've put him in the [No.] 4 but I'd have three lefties in my first four hitters against a left-handed pitcher," Yost said.

So he decided to use Danny Valencia, his right-handed option to Mike Moustakas at third base, in the cleanup slot.

"I could've hit him second," Yost said. "Those were my two choices, to hit him fourth or second but late in the game they've got power right-handed arms and when they came back around, I wanted Hoz to get that at-bat. So we left it like that."

Valencia pointed out that he hit fourth four times for the Orioles in last year's September postseason race. He was 3-for-12 in those games.

Perez was resting a badly bruised left leg, giving him back-to-back days combined with Monday's off-day. He's expected to catch again Tuesday night against the Rockies.

Royals to play charity golf tourney on off-day

SEATTLE -- The Royals' open date on Monday will be filled by the seventh annual Royals Charities Celebrity Golf Tournament at the National Golf Club in Parkville, Mo. Among the eight or 10 players expected to play is pitcher Jeremy Guthrie.

"I love it," he said. "I don't play any of it during the season but I play a lot in Spring [Training]."

Other players expected include James Shields, Jason Vargas, Tim Collins and Mike Moustakas.

Manager Ned Yost will join members of his coaching staff in the sold-out tournament, which benefits the Special Olympics of KC Metro.

There's a shotgun start at 9 a.m. CT on Monday.

Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.