ST. PETERSBURG, Fla.— While much has been made of Daisuke Matsuzaka’s almost unprecedented 2008 season, it has been easy to ignore what might have been the most critical part. A trip to the disabled list may have been the pivotal event in allowing the Red Sox starter to claim victory in last night’s opener of the American League Championship Series.

The 28-year-old was sidelined for three weeks in June with a strained rotator cuff. That time resulted in a profound transformation of the pitcher’s routine. The result, suggested Sox pitching coach John Farrell, was the dominant performer who logged seven innings of shutout ball in a 2-0 win over the Tampa Bay Rays.

“He’s in a different physical state this year as compared to last,” said Farrell. Last year, he was dealing with some fatigue in the second half of the season in ’07. This year, that hasn’t been the case. In that respect, he is a different pitcher.”

A year ago, the Sox believed that Josh Beckett was positioned to dominate in the postseason in no small part because of a two-week stint on the disabled list early in the year with torn skin on his finger. He finished the regular season with 200.2 innings. When Indians starter CC Sabathia looked spent in the ALCS after throwing 241 regular-season innings, Beckett looked fresh.

Something similar may now be at work with Matsuzaka, who was limited by his injury and inefficiency to 167.2 innings in the regular season. Yet in his case, the impact of his time on the D.L. went beyond a mere period of rest.

Through May, the Sox and Matsuzaka had frequently struggled to find a shoulder and conditioning program that would satisfy all parties. Matsuzaka wanted to maintain the routine he had followed in Japan of throwing almost constantly.

The Sox were concerned that the smaller strike zone, deeper lineups, more rigorous travel schedule and diminished between-starts rest created numerous stresses for a Major League Baseball team beyond what a pitcher in Japan might face. The team had studied the fact that other pitchers such as Hideo Nomo showed sharp declines in their arsenals and performances over time.

“The Nomo trajectory is three years and then they start to decline because of the amount of throwing. The intensity is a little bit higher here because of the competition. We’re aware of that,” said Farrell. “(Matsuzaka) has had many conversations about that here.

“Not that he took that for granted. But we have continued to try to educate him along the way to what history has shown us, and how can we learn from that and use it to his advantage to be a more productive and longer career.”

The process of getting to that point was not easy. Sometimes, the two sides demonstrated give and take. In other instances, they seemed at odds about how Matsuzaka should stay sharp between starts.

His bullpen sessions often seemed like efforts to simulate almost a full game. Matsuzaka would throw 75-90 pitches in his side sessions, often more than doubling what his teammates would do.

No longer. Since his injury earlier this year, Matsuzaka (18-3, 2.90 ERA in the regular season) has bought into the team’s shoulder program. In recent months, he has scaled back to roughly 45-50 pitches between starts. The injury appears to have prompted him to embrace the methods that have typically proven so effective for his Sox teammates.

“Training methods are drastically different in the two countries,” said Farrell. “I think he understands better our shoulder maintenance program, why it’s so detailed, why it’s asked to be so diligent and consistent. And I think the fact that he missed some time with the shoulder injury made him a little more open-minded to this.”

Last night, he looked like a pitcher who was operating in peak form. He allowed four meager singles and four walks in his seven shutout innings. Matsuzaka struck out nine batters, tied for the fifth most by a Sox starter in franchise playoff history.

But his performance was probably even more impressive than those raw numbers. The life on his pitches was exceptional. He regularly touched 93 mph with his fastball throughout his outing, and he showed a masterful ability to throw his sinking two-seam fastball (also known as a shuuto) for strikes to the glove side of the plate.

“He threw a two-seamer to Carlos Pena that moved like a foot,” said Kevin Youkilis. “He looked unbelievable.”

He mixed those pitches with excellent movement on his cutter and slider to overpower the Rays for most of the evening. It did not, however, look like such a performance was in the offing from the outset.

Matsuzaka loaded the bases on three walks in a 27-pitch first inning, but managed to pitch his way out of harm by getting a bases-loaded force out from Cliff Floyd. No surprise there—Matsuzaka held opponents hitless in 14 at-bats (18 plate appearances) with the bases loaded in the regular season.

He cannot explain his success in such situations.

“It just turns out that I’ve been able to hold the runners with the bases loaded, and even when I’ve allowed runners on through walks, I’ve just been able to hold them there,” he said.

After the Rays missed that opportunity, Matsuzaka did not provide them with many others. From the second through sixth innings, he never allowed a runner past first, and he needed just 10 pitches to sail through each of the the fourth, fifth and sixth innings with a no-hitter intact.

(It was the longest that a pitcher had held an opposing team hitless in the postseason since Yankees pitcher Mike Mussina threw 6.1 perfect innings to start Game 1 of the 2004 ALCS against the Sox.)

Of course, it would not be a vintage Matsuzaka outing without some additional hint of drama. And so in the seventh, Rays left fielder Carl Crawford broke up with a hard single to right, and Cliff Floyd followed with a single to left to put runners on the corners.

Though the Sox were clinging to a 1-0 lead, they were prepared to concede the run if they could turn a double play. But that proved unnecessary, as Matsuzaka pulled one of his patented escape acts.

He retired Dioner Navarro on a shallow pop to left that could not score even the speedy Crawford. Gabe Gross then whiffed on a sinker, and Matsuzaka smothered the threat by getting Jason Bartlett to ground meekly to short for a forceout.

Matsuzaka, who held opponents to a .164 average (lowest among major-league starters) with runners in scoring position, once again proved capable of quashing a threat.

“It’s pretty fun to play behind, but a little nerve-wracking,” said shortstop Jed Lowrie. “He always seems to find a way to get out of it. He’s done an amazing job of getting out of tough spots. It’s almost unprecedented.”

Yet Matsuzaka continued to defy baseball’s laws of probability in part because he is pitching with plenty left in the tank. For that, both he and the Sox can be grateful for a mid-year trip to the disabled list that bought the pitcher time to both rest and reflect on the need to accept a program whose benefits were apparent last night.

“We’ve had a very open dialogue over the past two years to educate along the way to give him the freedom to pitch as he’s accustomed to,” said Farrell. “He’s been more open this year to lessening the amount of throwing he’s done between starts, and that’s what’s allowed him to remain strong and fresh throughout the second half of this season.”

Alex Speier is a Senior Writer for WEEI.com.