BOSTON -- Roy Halladay's perfect game Saturday night was just the 20th in Major League history, but comparatively speaking, there's been a positive glut of them recently -- two this month, three in the past two years and the eighth in the past two decades.

"I think it's just a quirky thing," Royals manager Ned Yost said. "On any given night here at the big league level -- they're all in the big leagues for a reason, because they're good -- if they can command their stuff like Halladay did [Saturday] night, the odds might be that you can throw a no-hitter.

"I mean, it's tough to do. You've got to be perfect with all your pitches, you can't make a mistake, and if you do make one, it's got to be your night that your mistake is hit to somebody. And I didn't get a chance to watch any of it, but I'm pretty sure there were one or two spectacular plays that saved that perfect game. I don't know, but that generally happens to be the case."

So Yost doesn't necessarily think pitchers are just bigger, better or smarter in recent times -- the perfect games and other no-hitters have just happened.

"I don't really read anything into it," he said.

Greinke concerned with slider's effectiveness

BOSTON -- Zack Greinke's 1-6 record obviously isn't the result of lousy pitching -- he's mostly been quite good as evidenced in a 1-0 loss to the Red Sox on Saturday night -- but he wonders about his slider.

That's the pitch that was his mainstay during his 2009 American League Cy Young Award season. This year, it's been much less effective.

"I was probably striking out like six guys a game last year on a slider, and now I probably do one or two a game. I still throw it, but I don't know why it's not working," Greinke said.

Greinke still believes in it, according to what he said in his postgame critique.

"It's a good pitch. It doesn't matter if they know it's coming or they've seen it a million times. It's still a good pitch," he said. "But obviously, something's wrong with it. I don't know. And it's not really a pitch I can throw a hundred of them in-between starts or my arm will fall off."

Yost: Hard to temper walk-off celebrations

BOSTON -- Kendry Morales is lost to the Angels, who open a series at Kauffman Stadium on Monday afternoon, for an extended period because of a bizarre accident.

Morales, the Angels' most productive hitter, hit a game-ending grand slam that beat the Mariners, 5-1, on Saturday, and suffered a lower leg fracture as he leaped onto home plate amidst his celebrating teammates.

That might tend to defuse walk-off celebrations for a while, although Royals manager Ned Yost thinks it might be difficult to douse them completely.

"There have been thousands celebrations at home plate, and this is an isolated incident," Yost said. "I don't think you shut down celebrations when you have a walk-off win. I mean, that's the fun of a walk-off win -- the excitement that's generated because of it. You fight hard and you work and all of sudden, the game's over and your emotions pour out. I don't think you want to stop that.

"But we need to keep an eye on it and make sure it tempers down a little bit."

Yost had another thought about it.

"All I know is I would like to practice our walk-off celebrations a lot more than we have this year," he said.

Bloomquist takes on Green Monster

BOSTON -- Willie Bloomquist took on Fenway Park's Green Monster as the Royals' left fielder in Sunday's 8-1 loss to the Red Sox.

He was kept busy chasing balls hit off or near the famous wall.

"It was fine. It was a little bit weird, because the wall's right behind you," Bloomquist said. "There were a couple balls that I thought I could've caught, but you go back and you run into the fence. Obviously that's the tricky part about the wall out there, but I don't think I screwed up too bad out there."

Manager Ned Yost said he was confident in playing the versatile Bloomquist in almost any spot. In this case, playing left field in place of Scott Podsednik gave Yost another right-handed bat against lefty Jon Lester, although Bloomquist went hitless with one walk.

Yost also rested catcher Jason Kendall, who didn't start for just the third time in the team's 51 games. Backup Brayan Pena took over and got one of the four hits off Lester.