Replacements for McClure and Gibbons were not announced at a news conference at Kauffman Stadium.
Yost said that the Royals would search outside the Kansas City organization for a new pitching coach. That eliminates Minor League coaches such as Omaha's Doug Henry and Northwest Arkansas' Larry Carter.
"I'm looking for a guy that pitched in the big leagues for a long time with mediocre stuff," Yost said. "Usually those guys that have to work real hard at their game and have longevity in their game are going to make dynamic pitching coaches."
He held up as a prime example Mike Maddux, his pitching coach when he managed the Milwaukee Brewers. Maddux is currently Texas Rangers pitching coach.
The new catching and bench coach likely would come from "in-house," Yost said, although that is still being discussed. He wants a Spanish-speaking coach who can work easily with Latino catchers Salvador Perez, Brayan Pena and Manny Pina.
A likely candidate under those qualifications would be Chino Cadahia, now with the Royals as special assistant to player development. A former catcher and catching coach, he was bench coach for Atlanta Braves manager Bobby Cox for four years.
Yost said the coaching changes had been discussed for about six weeks and the decisions were made about two weeks ago. Parting ways with McClure, a former Milwaukee teammate, was difficult.
"It was extremely hard. We were real close," Yost said.
Yet what Yost saw and what the statistics told him indicated a "new voice" was needed for the Royals pitchers. They ranked 12th among the 14 American League teams with a 4.44 ERA and yielded the most walks, the third-most hits and the fourth-most home runs in the league.
"We just threw too many balls, we walked too many hitters, we're behind in the count far too much, which resulted in more hits than we'd like to see, more home runs than we'd like to see," Yost said.
"Bob McClure did a phenomenal job here for many years and had a great working relationship with these young pitchers, but we just felt as an organization it was time for a different voice."
A major problem, in Yost's view, was the inability of the Royals' pitchers to keep their pitches down in the strike zone consistently.
"We pitched up way, way too much and pitching up is a result of mechanics," Yost said. "We just consistently pitched up too much and we knew we had to find a way to get the ball down. So that's going to be a consistent focus. It was a consistent focus for us this year, but we just couldn't accomplish it."
McClure, 59, was the Royals' pitching coach for six years and served under managers Buddy Bell, Trey Hillman and Yost. He began his playing career with the Royals in 1975 and pitched for 19 years with seven clubs. He was the Colorado Rockies' Triple-A pitching coach when the Royals hired him in 2006.
"I can't say I was shocked, I kind of felt something was coming," said McClure, after returning to his Florida home. "It was disappointing because you could see them getting good; a couple of more pieces and it's going to be difficult to beat us on a daily basis."
In addition to helping a large influx of rookie pitchers, McClure was especially pleased about the second-half improvement this year of Luke Hochevar and the resurgence of Bruce Chen in the last two years.
"I was proud of what a lot of the guys accomplished," he said. "I thought Hoch came a long way and it was exciting to see Bruce do what he did. We changed everything mechanically and just re-started him from scratch. That was really a neat thing to see."
McClure said he believes that Kansas City's time is coming and he's disappointed he won't be there to take part.
"We respect him a great deal," general manager Dayton Moore said at the conference. "I've never been around a pitching coach or a coach period that worked so well with everybody within the organization. ... He taught me a lot personally. It's a very tough call -- he and John Gibbons both. There's no finer person in the game than John Gibbons."
Gibbons, 49, served as the Royals' bench coach for three years under Hillman and Yost. A former catcher, he was a successful Minor League manager and then managed the Toronto Blue Jays from 2004-08 with a 305-305 record. Last winter he was mentioned as a candidate for vacant managing jobs including the Mets.
The change caught Gibbons somewhat unaware when informed of it on Tuesday.
"They said they wanted to make a change and they didn't go into details and I didn't need that anyway," Gibbons said as he drove back to his Texas home. "I've learned in this business to always expect the unexpected. There's always going to be some kind of change. But I really enjoyed my three years there. I just wish we'd have won more games."
Gibbons agrees with a view that the Royals are on the rise.
"There's a heck of a lot of young talent and they're in the right division, too. This division is up for grabs if you play good," he said.