Oakland is in sort of a growing-pains period. Key players are gone, and the front office is focused on the future, but there are games still to play and important series coming.

“We’re still trying to do the best we can to string some wins together and try to get closer to .500 and then you never know what can happen,” manager Bob Melvin said before Wednesday’s 7-3 loss to Baltimore. “We’re still playing with some urgency to put together a streak, no matter who we’re playing.

“Once you get into September, you have a better idea where you are in the standings and then maybe you look at being a spoiler, but I don’t think we’re there yet. We still have a lot to play for.”

Oakland’s decision-makers moved Ben Zobrist, Scott Kazmir and Tyler Clippard before the trade deadline, and with the A’s in last place, the team is auditioning some players for next year while trying to win.

Thursday’s starter, Aaron Brooks, got a look-see Saturday, had a great Oakland debut and landed a rotation spot. Arnold Leon, Wednesday’s loser, is getting a chance in the bullpen. Infielder-outfielder Danny Valencia made his A’s debut Wednesday after being claimed from Toronto. He played third base and doubled in his third at-bat.

“We’ll always have a focus and emphasis on now. We don’t close that valve off,” Oakland general manager Billy Beane said. “We’ve targeted some younger players with more of an upside in trades as more of a long-term approach, but we’re always trying to get better in the short term, too.”

Beane said the time to evaluate the A’s really will come this offseason, but there’s no doubt that some of the next two months will be spent trying to sift through some options at the big-league level for roster decisions that will be made before next season.

The offseason, though, will be different from recent winters in one major respect: Oakland will not be dealing young players for proven big-leaguers, which has been the team’s recent MO. The A’s traded Addison Russell in the Jeff Samardzija deal and Daniel Robertson in the deal that brought Zobrist to Oakland.

“What we probably won’t do is use prospects for acquisitions,” Beane said. “That’s not to say we won’t make trades.”

The free-agent market, then, could be the spot for Oakland’s shopping needs, and though the team tends to be frugal, Billy Butler got a three-year, $30 million deal last winter and the A’s could be looking at more signings in that price range this winter.

A former A’s outfielder, Yoenis Céspedes, will be one of the most high-profile free agents, and there are some in the industry who believe he’d welcome a return to Oakland, but he’s likely to be too pricey for the A’s.

Long-term deals for some current A’s could be on the table at some point, though Sonny Gray is probably more than a year away from an extension because of the risk pitchers pose when it comes to long-term deals.

Melvin, however, is very much in line for a long-term extension, something that is likely to be announced at the end of the season.

It’s also a strong bet that the A’s will follow the trend of other teams in recent years and promote Beane to a team-president-level title and assistant general manager David Forst to general manager this winter, with Beane still maintaining overall control of major baseball decisions.

Susan Slusser is a San Francisco Chronicle staff writer. E-mail: sslusser@sfchronicle.com Twitter: @susanslusser