It has been nearly two years since his own likeness represented the career low point for Clay Buchholz.

On Aug. 20, 2008, after he was swallowed by another loss — this one to the lowly Orioles in Baltimore — the Red Sox gave Buchholz news that hardly came as a surprise. He was being sent down to Double-A Portland. Yet the demotion was only the start of the misery.

Sea Dogs manager Arnie Beyeler and pitching coach Mike Cather offered the pitcher a welcome mat when he arrived in Portland the next day. The two had dogged Buchholz for eating too much candy in the clubhouse in the 2007 season, but upon his return to the Sea Dogs clubhouse, Buchholz had a full bag of candy waiting in his locker from his manager and pitching coach.

But while that gift offered some amusement to all three men, Buchholz almost immediately found out that humiliation was close at hand.

“He came down and we said, ‘How are you doing?’ He said, ‘Man, my head’s spinning. I’ve been doing this, doing that,’ " Cather recalled. “I said, ‘I just want to give you what’s going to happen. It’s your bobblehead day when you get back for your first start.’

“He said, ‘You’ve got to be kidding me,’ ” Cather continued. “I said, ‘It’s been on the books for a year. You’re starting your own damn bobblehead night. Worst thing that can ever happen. So, this is a challenge.’

“He said, ‘[Expletive] me.’ I said, ‘Yep — just wanted you to know, this is the stuff you’re going to be going through.’ He said, ‘Forget it, let’s go.’ ”

Tail between his legs, Buchholz made his return to the mound in Portland on Aug. 25, 2008, getting a no-decision.

Perhaps, somewhere, Buchholz has one of his bobbleheads from that night. Ultimately, it would be appropriate if he did so, since that game marks the beginning of the pitcher who is now one of the game’s elite.

Buchholz tossed six scoreless innings on Sunday against the Blue Jays, leading the Sox to a 5-0 victory. (Recap.)

He improved his record to 15-5, and dropped his American League-leading ERA to a svelte 2.26. Buchholz has not given up an earned run in 23 1/3 innings, the longest such streak of his career.

There is a giant distance that has been traveled from that point, two years ago in 2008, to the present. Yet Cather suggests that the two cannot be thought of as different times, and that instead, the end of the ’08 season in Portland and then the Arizona Fall League must be evaluated as the beginning of an ace’s formation.

“When he originally got sent down, I told everybody, ‘This is the best thing to ever happen to this kid.’ People would look at me like, ‘What the heck are you talking about?’ ” Cather said with a chuckle. “To me, it was a necessary evil. It was something that definitely had to happen in his career for him to truly understand himself.”

A (SEA) DOG, AGAIN

It was no small thing for Buchholz to be open to input after getting demolished in the majors in 2008. He went 2-9 with a 6.75 ERA, and often seemed like a deer in headlights as his defeats mounted.

He seemed terrified, at times, of attacking hitters, throwing over to first base time after time, even when a baserunner barely had a lead. And he seemed to have no real confidence in his fastball, seeming almost desperate to get opposing hitters to chase his curve or changeup out of the strike zone.

In the majors, Buchholz was overwhelmed. Yet he did not merely retreat upon his return to Portland. He actively sought support that would help him return to the career track that had sent him zooming through the minors in the first place.

Most notably, Cather thought, was Buchholz’ active interest in talking to Bob Tewksbury, the organization’s sports psychologist.

“[Buchholz] actually reached out and was looking for help. That’s the best situation that you have,” said Cather. “He had a chance to take a real deep breath, reformat himself and say, ‘This is how I’m going to go about my business from now on.’ ”

The right-hander, who had turned 24 earlier that August, had just two starts in Portland. But there was a great deal of promise in the outings. As one would expect from a pitcher who had thrown a no-hitter in the majors, Buchholz proved dominant, striking out 18 and walking just one in 15 innings on his way to a 1.80 ERA.

But it was the process that the Sox viewed as so promising. The time in Portland seemed like a building block. That, along with the organization’s desire to have Buchholz build his innings load for the year, led the Sox to send the pitcher to the Arizona Fall League.

Even so, while such an assignment was in the pitcher’s best interest, the subject of prolonging his season was an uncomfortable one.

“When it came down that they wanted him to go to the Fall League, I was thinking, ‘I don’t think anybody wants to ask him,’ ” said Cather. “He thought about it for about two hours and he said, ‘You know what? Let’s go.’ That was the biggest hurdle.

“The last thing you want to do is extend a season that’s gone really poorly, and he was going to extend it for another month and a half. For him, it was a big thing to say, ‘I’m actually going to sacrifice something right now for my career.’ That commitment, I think, was maybe the largest commitment’s he made to that point.”

ACING ARIZONA (AND BEYOND)

Buchholz did not want to go to Arizona. He wanted the 2008 season to be over. But he recognized that it was necessary, even if undesirable, and so he went.

Pitching mostly against players with far less professional experience, and certainly far less minor league success, Buchholz dominated out of the gate in the AFL. Cather, his pitching coach in Arizona, posed a simple question: What was at the root of the success?

“I said, ‘I know I can get these guys out. My problem is in the big leagues. I can’t get those guys out,’ ” Buchholz recalled. “He said, ‘Why don’t you think that same way?’ That’s sort of where it turned for me. … The rest is history.”

It was in the Fall League where Buchholz truly cemented some of the gains that he’d made in the season-ending weeks in Portland. Of particular significance was his willingness to cast aside his curveball and compete in various stretches solely with his fastball.

Whenever Buchholz ran into trouble during the 2008 season, it seemed, he would run away from his fastball, feeling that contact was a bad outcome. But in Arizona, he experimented with pounding the strike zone, to positive effect.

“To me, [the curveball] was his pacifier,” said Cather. “Kids don’t like giving up their blankets. Giving that up, that was a thing where you said, ‘This kid’s ready.’ He was learning how to pitch with his fastball and create angle and locate pitches down.”

Buchholz was effective, and yet, his effectiveness was of a kind to which he was unaccustomed. It was not dictated by strikeouts so much as it was by weak contact. The right-hander was initially distrustful of the development.

“He was in the Fall League, and he said, ‘I’m not striking anybody out,’” said Cather. “I said, ‘Do you think you ever need to learn to strike anybody out? You know how to strike people out. You just don’t know how to get people out. You need to learn how to get people out.

“ ‘You’re going to be in situations where you need to strike people out, but right now, you’re trying to strike people out in 2-0 counts. That ain’t gonna happen.’ ”

Buchholz had a reasonable tally of strikeouts, accumulating 17 in 21 innings in the AFL. But the more important lesson for the young right-hander was that a well-located fastball could produce either outs or a relatively harmless hit.

He gave up just one homer in his time in Arizona, and when he showed up to spring training in 2009, his approach was strikingly different than it had been the previous year.

“He said, ‘In order to be a pitcher in the major leagues, I know I need to use my fastball.’ He did,” Cather said. “It was almost to the point where you would think, ‘OK, ace, now you’ve got them set up for the curveball.’ Here comes another fastball and you’d think, ‘Holy cow.’ Then it was almost to the point where you’d go, ‘You know you still have an out pitch in there somewhere?’ ”

Yet that spring, Buchholz started manipulating his fastball, and proved capable of overpowering opposing hitters (whether minor league journeymen or more notable big leaguers) by attacking.

The curveball was rarely seen. Even the changeup made infrequent appearances. Buchholz started firing away with low to mid-90s two- and four-seam fastballs that resulted in consistent poor contact. It is an approach that has stuck with the right-hander.

“When he first came up, he was four seam, straight change, big curveball. You’re going to have some swing and miss and you’re going to have some louder contact when you miss with that fastball over the middle,” Sox manager Terry Francona said. “Now he’s cutting it, sinking it, he is getting contact, but it’s in the zone.”

It was in spring training of 2009 that Buchholz’ philosophical shift on the mound was apparent. The strikeout was a goal to be sought with two strikes, only after the opportunity for an early-contact out had passed.

“If there’s two strikes, anybody that can strike out somebody is trying for a strikeout. You don’t want them to put it in play if you don’t have to,” Buchholz explained. “Up until that point, strike one, strike two, throw it in the zone, let them hit it. If they hit it, hopefully it’s at somebody. That’s sort of the mind thought that I go through.”

He is now very much a pitcher with a plan on the mound. When he falls into old patterns, the ones that haunted him in the 2008 season, Buchholz feels that he is capable of making corrections in one pitch, rather than needing a game or a week to adjust.

As overwhelmed as he appeared just two seasons ago in the majors, he now exudes self-assurance on the mound. Sunday offered a case in point.

Buchholz walked the leadoff batter in each of the first three innings, and allowed five of the six leadoff batters he faced to reach base. He spent the entire afternoon pitching out of the stretch with runners on base.

Yet he was undaunted, holding the Jays hitless in six at-bats with runners in scoring position, and showing an ability to go for the kill with two strikes, punching out seven Jays with an explosive four-seam fastball and a darting changeup that gave his opponents fits.

In the span of just two years, Buchholz has gone from being viewed as a pitcher who was wasting his potential to one who seemingly has limitless potential. One of the worst pitchers in the majors in 2008, he is now very much part of the conversation — with just over a month left in the season — for the Cy Young Award.

It is a long way from making an ignominious minor league start on his own bobblehead night.

“It’s atypical,” Cather said. “You find out more about people when they’re going bad than when they’re going good. But the biggest thing is how quickly it takes them to turn that around. I think he showed a huge bit of character by how quickly he was able to turn it around.

“That was something that no one knew: Can he turn it around? How quickly can he turn it around? Is he going to be able to process it? I think he answered that question faster than most people thought.”