Miami ? Watching Dontrelle Willis play has, on occasion, left his catcher feeling ill and threatening bodily harm against the All-Star left-hander.

Paul Lo Duca isn’t entirely kidding. He’s one of many older, wiser teammates who’ve reprimanded Willis.

His indiscretion? Strange as this sounds, sometimes Willis just plays too hard.

“If you slide headfirst one more time,” Lo Duca tells Willis, “I’ll punch you right in the head.”

Other than his penchant for diving into bases, there’s not much else in Willis’ game that should anger his teammates. Despite Friday’s 9-6 loss to the Chicago Cubs, he is 13-4 with a 2.39 ERA.

Willis made the All-Star team in 2003, two months after his call-up to the majors. He’s clearly honored to return to the game.

“The All-Star game is for individual accolades, and I’m a team guy,” Willis said. “I know I’m not anything without the team.”

A little fame, a little money and a giant World Series ring from 2003 haven’t changed Willis, who still has the same mannerisms and attitude as when he left the anonymity of Double-A ball and joined the Marlins.

But as a pitcher, he’s definitely changed. Instead of throwing hard on virtually every delivery, he’s mixing speeds as well as any Marlins pitcher. He’s more refined, smarter about what to throw – and in what situation.

At 23, he’s growing up.

“He knows when to throw a ball,” said Josh Beckett, the 2003 World Series MVP. “He knows when to throw 93 and when to throw 83. That’s the biggest thing. It’s not easier, but with that funky delivery, he gets some pretty bad swings on pitches that are a foot outside. He knows that.”

Florida pitcher Dontrelle Willis works against the Chicago Cubs on Friday in Miami. At 23, Willis already owns a World Series ring.

That unorthodox high-leg-kick, body-twisting delivery still befuddles opponents, even those who’ve now faced Willis many times. He still wears his sweat-stained, flat-brimmed cap askew. And he remains one of the most exuberant Marlins, someone who yelps joyously when the latest video-game console arrives in his locker.

Manager Jack McKeon says Willis’ persona hasn’t changed one bit.

“He loves the game,” McKeon said. “He loves to compete. He loves the competition. He has fun. He dives into bases. And they say, ‘Ooh-hoo, that’s dangerous. Don’t you fine him?’ How do you take that out of him? That’s something that’s in there. That’s the desire to be successful. It’s sensational.”

Willis has no desire to talk about his gaudy won-lost record, glittering ERA, newfound role as ace of the Marlins staff, chances of being a 20-game winner or potential Cy Young candidate.

“It’s pretty refreshing, actually, to see a guy that has that much success that quickly and it doesn’t go to their head,” outfielder Jeff Conine said. “With the contracts they’re giving out and the signing bonuses, I think it changes mindsets quickly. But he’s continued to be humble and play the game with a lot of passion.”

The Marlins rave about his work ethic. Willis often is one of the first players at the ballpark, especially on days when he’s not pitching. He lifts weights for 30 minutes after every start. Often, he’s throwing or running in the outfield when the South Florida sunshine is at its absolute hottest.

That’s why he’s forgiven for grievous lapses in judgment like the one in Atlanta on June 23, when he dove into first for a bunt single while beating the Braves 8-0.

“I wish he wouldn’t do that,” Marlins first baseman Carlos Delgado said. “But you have to appreciate everything he brings to the table.”