Barry Zito wants to have the same tempo with each pitch. Dan Haren doesn't want to pause during his delivery. Huston Street doesn't want to rush. And Kirk Saarloos is concerned with his arm angle.

Each pitcher has little things that they worry about with their mechanics before they go into a pressure-packed situation in front of thousands of screaming fans.

Before the A's pitchers run into that climate, they rely on a little guidance from Brandon Buckley.

Buckley, the A's bullpen catcher, is probably best known for his brief mention in the bestselling book "Moneyball," but he has also been with the team since 2002 and knows the tendencies of each pitcher.

"He sees everyone throw throughout the week, and catches everyone before the game," Haren said. "He really knows what works with the pitchers; you wouldn't think that of a bullpen catcher.

"But he does a great job relaying things to us. He has helped me out quite a few times in my two years here."

The most recent example of Buckley's advice to Haren was on Friday against the Devil Rays. Buckley noticed that Haren was pausing too much during his delivery and falling off toward first base. Haren started off a little shaky, but went on to hold the Rays to two runs (one earned) over seven innings for his fourth straight win.

Haren isn't the only one boasting Buckley's name. There is also closer Huston Street.

Most people would have an anxiety attack if they were in Street's cleats every day. Closers are known for being pumped before entering a game and Street said Buckley helps him "stay locked in."

"He just helps you make your adjustment before you go out there," Street said. "Your stuff is different every day you go out there, especially for me as a closer. He pretty much tells me every single time if I'm working too fast or I'm coming to the plate too quick.

"When I ask him, 'How was my slider or how was my fastball?' he gives me an honest answer. He'll let you know if it wasn't a good one, and I respect his opinion. His feedback is awesome. You want to be able to trust your catcher, whether it is in the game or in the bullpen."

Buckley can't take credit for getting a win for Haren or a save for Street, but he has been a catcher since he went to San Ramon Valley High School in Danville, Calif., and went as far as Double-A after being drafted by the Astros in 1998.

The 29-year-old said he would like to be a bullpen coach in the future, and he credits being around great coaches and pitchers for earning the respect of the hurlers.

"I have been really fortunate to work for four of the best pitching coaches in the game," said Buckley, who went to Texas Tech University, referring to Jack Billingham, Rick Peterson, Dave Stewart and current A's pitching coach Curt Young. "And just being around those guys and taking some of their knowledge and how they work with pitchers helps me out every day working with these guys."

Buckley catches the starters twice in between starts and the relievers before they come in. And whether it is a righty with a 95-mph fastball or a lefty with a sweeping curveball, everyone is a little different.

"Each guy has one or two things that are constant maintenance issues," Buckley said. "With some guys it is their arm angle, some guys it is their pace and rhythm, and some guys don't want to be told anything [because they] like to figure it out on their own.

"A guy like Zito wants to know if he's got a different tempo with his delivery when he is throwing a changeup or a fastball. Huston wants to warm up in a nice easy pace and ease into it, and the same thing with [reliever] Chad Gaudin."

To a casual fan, Buckley looks to be just playing catch with pads and a mask. But there is more there than meets the eye.

"Buckley is absolutely involved [with the pitchers]," Street said. "Buckley is absolutely a major [part of] my success on the field, and if I could speak for everyone, he's a part of our pitching staff's success."

"He's been here basically as long as every pitcher here, with the exception with Barry," Saarloos echoed. "He knows [our] mechanics. He doesn't come running out telling you to do this or that, but if you ask a question, he definitely has an answer for you. Everybody takes what he says to heart. He's like another pitching coach."