CHICAGO – If White Sox pitcher Jake Peavy needed to scream or swear or bang his head against a wall Tuesday, he got it out of his system before his postgame interview.

By the time Peavy walked to his locker 30 minutes after the final out of a 2-1 loss to the Cubs, his emotions were in check. He stood calmly in gray flip flops, black shorts and a sleeveless T-shirt and reminisced on his second complete-game loss of the season.

“It wasn’t meant to be,” Peavy said. “You’ve got to pick it up and you’ve got to be a good teammate tomorrow, and [we’ve got to] show up and find a way to win.”

Clearly, this is the region’s most well behaved bulldog.

The Sox wasted Peavy’s gem, lost another series and slipped out of first place in one fell swoop against the last-place Cubs. Peavy limited the Cubs to one earned run in nine innings and 125 pitches, but his teammates did him no favors with an untimely error by third baseman Orlando Hudson, a botched ball in the dirt by catcher Tyler Flowers and a nine-pack of hitters that proved to be quieter than an empty upper-deck seat.

“He deserved better,” Sox manager Robin Ventura said of his tough-luck starter.

In retrospect, Peavy also deserved better than what the skeptics (myself included) had to say about him this spring.

Hopefully, we thought, he could stay healthy long enough to become trade bait. But then we rolled our eyes and asked ourselves why anyone would want to absorb that monstrosity of a contract that included $17 million this year and a $22 million club option next year.

In the blink of a fastball, Peavy has silenced his doubters.

Forget shopping Peavy on the trade market. He’s the Sox's most important pitcher in what is shaping up to be a summer-long run at an AL Central division title and a playoff spot.

For the previous two-and-a-half seasons, Peavy was the great unknown in the Sox's starting rotation. He started three games in 2009, 17 games in 2010 and 18 games in 2011 as he battled a parade of injuries that would have impressed a retired NFL player.

Through 14 starts this season, he has reversed course to become Mr. Reliable.

Peavy, 31, has emerged as one of the most pleasant surprises on a Sox team filled with them. He is 6-3 with a 2.74 ERA, and he has allowed fewer walks and hits per inning than all but three starters (R.A. Dickey, Matt Cain and Jared Weaver).

Those statistics would be impressive regardless of the circumstances.

They’re especially important given the other problems in the Sox rotation.

John Danks, the Sox’s opening day starter, is sidelined indefinitely because of a shoulder strain. Indefinitely is a great adjective if you’re talking about the duration of a paid vacation or consecutive days of sunshine, but it’s a horrible word to describe a pitcher’s injury status.

The rest of the Sox starting rotation also needs Peavy to ace the next three-plus months.

Gavin Floyd is talented, but he’s way too inconsistent. Chris Sale looks like the real deal, but he’s 23 years old and has started 12 career games in the majors. Fellow southpaw Jose Quintana has started five.

Sox captain Paul Konerko said Peavy’s value was obvious.

“Peavy's been great all year,” Konerko said. “I think every start he's been out there, he's given us a chance to win.”

Next time, the Sox need to capitalize on that chance.

• Tom Musick covers Chicago sports for Shaw Media. Reach him at tmusick@shawmedia.com.