CHICAGO -- The lasting image of Rick Porcello from his rookie season was his poise on the mound at the Metrodome last October in the American League Central playoff against the Twins. The Tigers have to hope that Wednesday doesn't end up the snapshot of his 2010 campaign.

At the very least, however, the 15-3 Tigers loss to the White Sox found a new depth to his sophomore slump.

Two words from manager Jim Leyland summed it up: "I'm concerned."

Porcello was again calm in the face of pressure, but he couldn't keep the hits from falling all over U.S. Cellular Field in a seven-run fourth inning. He gave up five straight hits so quickly that he didn't quite grasp it. When he finally caught his breath with an out, Ramon Castro knocked it out of him on his next pitch with a three-run homer.

The young man, who retired nine of the first 10 batters he faced, gave up six runs in a seven-batter span and retired only one of his final eight batters.

"They got those hits so quick, it was like a slap in the face," Porcello said. "I didn't even realize what happened until I was out of the game. That's a perfect example of just letting the game speed up on me, and I've done that a couple times this year and not been able to stop it."

To be fair, most 21-year-old pitchers are still coming up through the Minor Leagues. Many pitchers who graduated high school at the same time as Porcello were drafted as college pitchers in the past few days. Porcello is battling to stay afloat in the big leagues with a breaking ball that has flattened out.

"He just hasn't been able to do much with his breaking ball at all," Leyland said, "and he basically tried to pitch with one pitch. The breaking ball was not doing anything. It was just spinning."

Porcello, too, is struggling to find the reason. He went into the clubhouse after his outing and immediately went to the video of his undoing.

"I watched those at-bats several times," Porcello said. "All three of those breaking balls that they hit, they were just hanging right there. The one to [Alex] Rios for the base hit, and then [Paul] Konerko, and then [Gordon] Beckham. And the fastballs, they just stayed up. They were more middle half [of the plate] than in.

"You're not going to get guys out with those types of pitches. I mean, those guys were just ready to pounce on it. They're looking to put runs on the board. They're struggling, too."

Rios was the second straight hitter Porcello fell behind to start the fourth inning, and he lined a pitch to right. Two pitches later, Konerko took the breaking ball and lined it off the left-field fence. Beckham hit Porcello's 57th and final pitch off the fence in left-center for a double, his first extra-base hit since April 29.

With just 3 1/3 innings, the only quicker exit Porcello has made came not from an offensive onslaught, but a fight with Boston's Kevin Youkilis last August. Chicago's eight earned runs marked a new career high. His ERA for the season jumped from 5.25 to 5.95.

The questions of what the Tigers can do about Porcello's struggles are likely to be raised as well. Pragmatically, the seven-run eighth inning the White Sox put up on Eddie Bonine and Fu-Te Ni was academic by comparison.

Asked if Porcello is spinning his wheels, Leyland cautiously agreed.

"I would probably say there's some truth to that," he said. "I don't know if I'm accurate, but if you're asking me which way I would lean, I would say that's probably a possibility, yeah. That's probably a pretty good observation. Am I right? I don't really know that, but my gut would tell me yes.

"I think there's some frustration there that probably has never been there before. It's just a matter of getting it worked out."

That might be the first time the Tigers have used the term frustration with Porcello. But then, he has never had struggles like this before, not just professionally.

"It's not outthinking," Porcello said. "I'm honestly just trying to get guys out. It's not like I'm trying to outsmart anybody or anything. It's not just doing what I want it to."

Theories abound as to why Porcello hasn't recaptured his 2009 form. An inconsistent sinker has been a common theory, while the balance between two-seam and four-seam fastballs is another possibility. Before Wednesday's game, Leyland again raised the idea that Porcello is actually still growing, and is still learning to pitch with a bigger body frame.

They've had time to work on it, but haven't solved it so far. The breaking ball, Leyland said, has been "hit and miss all year with Rick."

It isn't as simple as asking whether Porcello can work his way through these issues in Detroit's rotation. It would not be a stretch to say that the Tigers' fortunes hinge on an effective Porcello every fifth game. Other pitchers can step in, but few have Porcello's potential to work through a game.

That potential is still there, but the progression hasn't been. This doesn't take away his potential by any means, but the present results aren't pretty.

"There's no doubt in my mind that I can go out and pitch well in my next start, keep us in the game," Porcello said. "There's no reason why I can't do that. Today, I lost track of what I was supposed to be doing. I got hurt for it. But there's no reason why my next start, I can't go out there and bear down and get these guys out. There's nothing wrong with any of my stuff except for just making quality pitches. I have to stay focused every single pitch."