This is why Justin Verlander pushed himself physically through an offseason workout routine he fine-tunes with each passing winter.

This is why Verlander threw so many Spring Training pitches with a perfectionist attention to detail, looking for how the ball moved, how hitters reacted, even asking umpires about a low and inside curveball or two.

This is why Verlander cared enough to argue why his pickoff move is not a balk with umpires in his final Spring Training start last weekend.

From his final start of 2010 until now, he wanted to be able to step onto the mound at Yankee Stadium on Opening Day and feel like it's May or June. His April numbers reveal why.

"Just trying to set the clocks forward a month," he said earlier this month, "treating this as if it's April, and working on the things I need to work on to get myself in the form that I [normally] get to in May and June."

In other words, Verlander is looking for his midseason form now. If he finds it, there's no telling what he might accomplish this season.

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"Who knows? I definitely don't feel like I've reached my potential yet," Verlander said. "I can make strides to get better, and that's what I'm trying to do. And I think this is something that's going to help me. I firmly believe that."

His manager agrees.

"He's had a tremendous concentration level all spring," Jim Leyland said. "I think it has paid dividends for him, if he can take that into the season, which I think he will. He's had a very productive Spring Training, I think, in a lot of different areas."

Verlander's opening month has been an obstacle to that. After five full Major League seasons, he enters 2011 with an 83-52 record and a 3.81 ERA. He averages 16 wins a season, and he has won at least 18 in three of the last four years. In March and April, however, he's 7-11 with a 5.06 ERA. Three of those wins came as a rookie in 2006, with single wins in each of the four seasons since. The last three opening months, he has given up 64 earned runs over 91 2/3 combined innings, good for a 6.23 ERA.

Those struggles have started with Opening Day. Thursday will be his fourth season-opening assignment. He has a loss, two no-decisions and no quality starts in his previous three.

Each year, he has felt like his stuff was there, but he couldn't put everything together. In 2008, his early problem was velocity, enough so that some wondered if he was injured. The last two years, he threw too many pitches to get through too few innings.

It isn't hard to see what a good opening month would've done for him. The elusive 20-win season, the Cy Young Award, all are easily within reach.

This year, he did something about it. As soon as his 2010 season ended, he looked into his offseason workout routine and what he could do for that. The bigger change came when he arrived at camp. It wasn't simply about getting in his work. Every pitch had a purpose and an expectation. His first official bullpen session of camp saw the same competitive scowl and the same reaction to a missed location that he might have in a game.

"He came in with a plan," new teammate Brad Penny said. "I haven't seen too many guys come into Spring Training with a plan, other than to get their work in. He told me when he got here that he struggled early on. I don't know how. If he had a plan, he overachieved this spring."

The common train of thought is that pitchers are usually ahead of hitters when Spring Training games begin, then the playing field evens by the midway point. Against Verlander, hitters never caught up.

It wasn't simply Verlander blowing fastballs by hitters who had yet to get their timing down. Verlander mixed his pitches like he would in a regular game, and he would change his approach with each turn through the order. He started his fastball at a comfortable velocity and worked his way up, only bringing out the upper-90s heater late in his pitch count or in select situations early.

"That might be the best spring I've ever seen out of a pitcher," said Penny. "He had no hiccups. He said he was going to do it and he did it."

If Verlander is at the top of his game, hitters shouldn't have much of a chance. His command should allow him to locate the kind of inside fastballs that leave batters hurting when they make contact up the bat near their hands. He can then make hitters so eager to hit pitches on the outer part of the plate that they'll chase.

Verlander hasn't been able to find that command from the outset in the past. He hopes he has it now.

"I accomplished what I wanted to," Verlander said. "I feel like I did everything I could. We'll see how it translates in April."

Actually, the first measure comes on the last day of March.