Oakland, Calif. ? When the Oakland Athletics put together their biggest month-to-month improvement in 25 years, manager Ken Macha said it couldn’t last. When they went from 15 games under .500 to a winning record, he repeated it.

And now that they’ve followed up their remarkable June with an even better July, Macha is sticking to the same line.

“It would be nice to be able to stay this hot, but I don’t think that kind of thing happens very often,” he said.

Remarkably, it’s happened twice in one season. Both wild-card leaders – Oakland and Houston – were 15 games under .500 in May. Only one team has ever made the postseason after falling so far under the break-even mark, the Boston Braves in 1914.

“It’s awesome, but we can’t get complacent,” A’s starter Barry Zito said. “It’s only July. We would like to win the West, but there’s still a third of the season left. I’m sure all of us would like October to come sooner than it is.”

The A’s followed up a seven-win May with 19 victories in June – matching the biggest turnaround in Oakland history – and then did one better in July, going 20-6. They entered August having won 11 of 12 and 41 of 55 since dropping to 17-32 after May 29.

The biggest sign of the turnaround might be that the trade deadline passed Sunday without general manager Billy Beane involved in trade talks.

Oakland pitcher Barry Zito works against Detroit. Zito, shown Saturday in Oakland, Calif., and the sizzling Athletics have won 41 of 59 games since May 29.

The sell-off of veterans that some anticipated when the A’s were languishing in last place was unnecessary. And after making two quiet deals at the All-Star break for Jay Payton, Joe Kennedy and Jay Witasick, Beane didn’t see much else out there to help his team make a playoff push.

These second-half turnarounds are nothing new for Oakland, which won 14 of its first 17 games after the All-Star break. The A’s have been far and away baseball’s best post-break team since 2000, a key factor in their playoff runs from 2000-03.

But this year was supposed to be different after aces Tim Hudson and Mark Mulder were traded in the offseason. Even though Oakland withstood the departures of Jason Giambi, Miguel Tejada, Johnny Damon, Jason Isringhausen, Keith Foulke and others in recent years, many thought the breakup of the “Big Three” would end Oakland’s run as a small-market contender.

That all changed once last year’s AL Rookie of the Year, Bobby Crosby, returned May 30 after missing nearly two months because of broken ribs. It continued with an infusion of energy from four key rookies – Dan Johnson, Nick Swisher, Huston Street and Joe Blanton.

The pitching staff was the biggest question mark after losing Hudson and Mulder. But with Zito back to his Cy Young form of 2002 and Rich Harden pitching like the ace Oakland thought he could be, the A’s are still strong at the top of the rotation.

And with Street solidifying the closer’s spot just a year after leaving the University of Texas, the A’s are getting noticed.