OAKLAND, Calif. (AP) – Rich Harden was sitting with his luggage on a shuttle bus at the Memphis airport last month, headed for a starting assignment at the Triple-A All-Star game, when his cell phone rang. It was the call to the big leagues.

A few days later, he amused many of his new teammates with the Oakland Athletics when he carried those same bags down to the hotel lobby instead of relying on a bellboy.

“You’re not supposed to do that, apparently,” the 21-year-old right-hander said with a grin.

Almost everything else about the majors has been incredibly easy for the Canadian right-hander, who’s the talk of the AL after four straight phenomenal starts in the A’s already loaded rotation.

With a fastball reaching 98 mph, a nasty split-fingered pitch and a mental toughness that belies his youth, Harden allowed just four runs in his first 27 major league innings. He beat the Detroit Tigers 7-2 on Tuesday night, improving to 3-0 with a 1.33 ERA.

In short, Harden is living up to every bit of the hype that has surrounded him for the past two years. Oakland already has Mark Mulder, Tim Hudson and AL Cy Young winner Barry Zito in the best young rotation in baseball – and now, the A’s just might have a fantastic foursome.

“He’s a pretty special kid,” A’s general manager Billy Beane said. “I’ve likened his last couple of years to the process we went through with our other three pitchers. We really thought he was going to be pretty good.

“I’m not sure we always thought it would happen this fast, but you just want to stay out of the way of that development.”

Beane and his assistants and scouts have well-earned reputations as astute talent judges, but Beane didn’t envision Harden as such a diamond when the A’s first found him in the roughs of Victoria, British Columbia, and an Arizona junior college.

In fact, Harden’s success has been a product of work and growth since Oakland made him a 17th-round draft pick three years ago. Harden, a former hockey player who gave up pucks in high school, didn’t even start pitching seriously until college – and he has added 35 pounds of muscle in the last two years from weight training.

Harden has no problem asking the rhetorical question that’s on every other team’s mind: “Who would have guessed I’d turn out the way I am now?

“It’s pretty amazing. I look back at where I was two or three years ago, and it’s hard to believe I’m here now.”

It’s a bit early to class Harden with Florida’s Dontrelle Willis and Arizona’s Brandon Webb in the 2003 crop of pitching phenomena, but nobody seems to have any doubt Harden is on his way.

Harden has certain things in common with each of Oakland’s Big Three. Physically, he resembles Hudson – another undersized right-hander with an arm that’s sometimes baffling in its strength. Harden’s father, Russ, has been actively involved in his son’s development, just as Zito’s father was.

And Harden rose through the Oakland system with a speed that hadn’t been seen since Mulder – and Zito and Hudson, of course.

After getting to know his Oakland teammates during an extended stay with the big league club in spring training, Harden started the season at Double-A Midland – where he pitched 13 perfect innings, retiring all 39 batters he faced.

“I never expected to start the season that well,” Harden said. “I didn’t have my good control coming out of spring, and they told me I was going to start at Double-A and probably keep me there the whole year. Then I got in there, and everything was working.”

He was promoted to Triple-A Sacramento, where he went 9-4. After starting for the World team in the All-Star Futures game last month in Chicago, he got the anticipated call from Oakland, where fans and media had been clamoring for him since April.

He was the A’s youngest starting pitcher in a decade when he beat Kansas City 7-2 on July 21.

Ten days later, Oakland’s fans got their first look at Harden. The muscled 6-foot-1 kid with perpetual stubble and youthfully unruly hair easily beat the Cleveland Indians, getting a standing ovation after every inning.

Mulder, Zito and Hudson were among the first to congratulate him after every success, but they’ve also tried to prepare him for adversity.

“At this level, it’s even more important to come back strong than it is to pitch well in the first place,” Mulder said. “Every major league pitcher has great stuff, but the key is to be tenacious when you don’t have your great stuff. That’s what you try to tell Rich.”

Harden played both baseball and hockey while growing up in Alberta and British Columbia, though he took to the ice more out of expectation than love. Still, the experience in a more physical game has translated into toughness – no surprise from a guy whose favorite hockey player is Tie Domi, the Toronto Maple Leafs’ diminutive enforcer.

“I wasn’t necessarily a fighter, but I was a little guy, too,” Harden said. “I loved to throw hits.”

After failing to make the Canadian national junior team as an outfielder, Harden pitched two seasons at Central Arizona Junior College, where he was a wild-throwing closer as a freshman.

“I’d go out in the ninth inning, walk two or three guys and get out of it,” Harden said. “I think that got me some good experience in tough situations, even though I did it to myself.”

Harden figures to encounter plenty of pressure during his first pennant run. The A’s essentially have made Harden their fourth starter, bumping Ted Lilly from a few of his scheduled starts to allow the Big Three to pitch as many games as possible until October.

Harden is having a fairly easy adjustment to Oakland off the field as well. His sister, Kristin, lives in the Bay area, and Harden has moved in with Mulder and infielders Frank Menechino and Mark Ellis, living in a house owned by Mulder in the hills of suburban Walnut Creek. Many of the young A’s have shared the house over the last three years.

“I like the pressure of coming up at this time,” he said. “Every start is important to the team, so everybody is behind me. Not everybody is in a situation like this to start their career. I’m fortunate.”

AP-ES-08-07-03 2116EDT