Tommy Milone, drafted and developed by the Nationals, has contributed much to Oakland’s recent surge. (Thearon W. Henderson/GETTY IMAGES)

The Oakland Athletics have many reasons not to be where they are. They have the second-lowest payroll in baseball at $55.4 million, missing the last-place distinction by $130,000. They have the second-youngest roster in the American League. They have one of the lowest-scoring offenses in the league, with their best hitter being a rookie from Cuba. Before this season, they traded away their past three all-stars for other teams’ prospects, including a trade that brought Gio Gonzalez to Washington this past winter.

Yet, the Oakland Athletics sit eight games above .500 as the season approaches the two-thirds mark in one of the highest-spending divisions in baseball, the AL West. They posted the best July in baseball, an impressive 19-5 record. They have the best pitching staff in the American League. They have 12 walk-off wins, the most in the majors. And, if you dare to dream: If the playoffs began now, this low-cost organization, whose innovative philosophy was depicted in the book and movie “Moneyball,” and its potpourri of players would make the playoffs as a wild card.

“We’re winning games the way we were losing games,” said Oakland outfielder-designated hitter Jonny Gomes, who played for the Nationals last season. “We’d make an error, throw the ball to the wrong base or something, and the other team would just totally capitalize on it. Now that’s what we’re doing.”

At the heart of the success of one of baseball’s most frugal teams is that trade that sent Gonzalez and a minor league pitcher to Washington for four of their best prospects — all drafted and developed by the Nationals. Washington felt it was a front-line starter away from contending, and Oakland could unload salary and bolster its farm system with young arms.

Two of those players have been in the majors this season, and none has contributed more to Oakland’s surge more than starter Tommy Milone, who made his major league debut last season with Washington. Gonzalez has been stellar for the Nationals, earning his second all-star selection and helping propel Washington into first place. It’s a trade that, for the moment, appears to have benefited both teams.

“At the time, it’s difficult to let guys like that go,” Oakland Manager Bob Melvin said. “And then you come to spring training and see what we got, and you’re pretty happy about that trade. I think both sides are very happy about that trade. That’s a little unusual, especially for the younger guys that we got. It usually takes a little more time. But we’re getting production out of some guys right now."

Oakland has risen to contention in the AL West against the Los Angeles Angels ($154 million payroll) and two-time defending AL champion Texas Rangers ($120 million) because of the strength of its pitching. Its meager offense, limited by its cavernous home stadium, has been boosted by Cuban defector Yoenis Cespedes, a power-hitting 26-year-old who signed with the team for $36 million over four years and has been one of baseball’s most pleasant surprises.

Milone, a 25-year-old left-hander, wasn’t as highly regarded as the other prospects in the deal. Baseball America’s ratings tagged right-handed starter Brad Peacock as the best of the bunch, and the Nationals’ third-ranked prospect, followed by right-handed starter A.J. Cole and catcher Derek Norris. But with injuries to three of Oakland’s starters, Milone earned a spot in the starting rotation to start the season.

And since, Milone has posted numbers somewhat comparable to Gonzalez. Milone’s ERA (3.68) is slightly higher than that of Gonzalez (3.27) and has struck out 40 fewer batters, but Milone has walked 25 fewer batters and has thrown 101 / 3 more innings. In 11 of his 21 starts, he has pitched at least seven innings.

Milone has thrived at home at the Coliseum, so much so that he has a 5-2 record and 1.51 ERA at home, but 5.77 ERA and 4-6 record on the road. He doesn’t have as electrifying stuff as Gonzalez, but he has a dangerous change-up and has already shown pinpoint command beyond his years. Gomes told Melvin during spring training: “This guy almost throws too many strikes.”

At first, Milone said it was tough to stomach the trade from the only organization he has known and spent four years in its minor league system. But he wasn’t sure if he would ever earn a spot in the Nationals’ crowded starting rotation.

“It’s hard to leave a place that treated me so well and the support they gave me,” said Milone, who still often checks Nationals results on his phone and iPad because he developed with players such as Steve Lombardozzi and Danny Espinosa in the minors. “But I couldn’t be happier with the opportunity I’ve gotten here.”

Norris, 23, made his major league debut on June 21 — sooner than even he expected — and hit a walk-off three-run home run in his third game. He contributed, mainly behind the plate as a backup catcher starting 20 games, before he was optioned to Class AAA Sacramento this week.

Peacock, 24, who represented the Nationals in the same 2011 All-Star Futures Game as Bryce Harper, has struggled at Sacramento, where he is 8-7 with a 6.17 ERA. Cole, 2o, a hard-throwing starter, has adjusted better at low-Class A Burlington after a hiccup at high-Class A Stockton. But they’re young, and the Athletics have high hopes for both.

Gomes, who played 43 games for the Nationals last season, said once he spent spring training with his new teammates he began seeing similarities with one of his former teams, the 2008 Tampa Bay Rays, who had the second-lowest payroll during that fairy-tale season.

“Excuse my ‘Bull Durham’ quotes and positive attitude, but I’ve been to the World Series with the lowest payroll,” Gomes said. “I’m living proof that it can happen.”