If you’re an A’s fan and you’re a crazy dreamer — you can’t be one without being the other — here’s a dream to dream, and it’s reality-based:

The Athletics lose their tasty slice of the MLB revenue-sharing pie. That cuts heavily into the annual profits of owners John Fisher and Lew Wolff, who pound a “For Sale” sign into their team’s front lawn.

The A’s are then grabbed by a person or group committed to quickly building a ballpark in Oakland. Imagine if Joe Lacob had a twin who is also light-years ahead of other sports people, who would launch a Warriors-like rebuilding, but keep the team in Oakland.

That’s the dream.

The Chronicle’s John Shea on Tuesday staged his annual All-Star Week inquisition of the baseball commissioner regarding the Oakland situation. Rob Manfred did some typical commissioner-style tap-dancing, but he did say something that Bud Selig would not say.

Selig’s annual comment to Shea on the A’s ballpark situation invariably was the super-duper-condescending and obfuscating, “It’s very complicated.”

Manfred, however, expressed MLB’s belief in Oakland as an increasingly viable major-league city.

The A’s rake in a tidy profit every season. For the better part of two decades, the A’s have received revenue-sharing checks, currently in the $34 million-per-season neighborhood.

The revenue-sharing money is supposed to be spent to improve the team on the field. You know, buy some good players, keep the good players you have, and provide a nice ballpark.

Apparently there is no real oversight on this, nobody in MLB checking to make sure the A’s are spending their rev-share money on baseball.

The A’s payroll, according to the salary-tracking website Spotrac.com, ranks 27th out of 30 teams, just above $101 million. By contrast, the Giants are No. 6, at almost $178 million.

The A’s keep their payroll low and regularly dump top players when they near big paydays (see: Josh Donaldson), thus assuring profits but fostering roster instability in a sport that thrives on stability (see: Giants).

Right now, there is some disincentive for the A’s to build a ballpark. Baseball fans, recent history says, will not blindly embrace a crummy team, even in a new ballpark. So whoever would build a ballpark, be it Fisher-Wolff or a new A’s owner, would be compelled to raise the payroll in order to attract and keep championship-caliber players, to keep the turnstiles humming. There would be no guarantee of the current profit stream.

Where’s the good news? Well, there is a clause. As Shea reported, when the current collective bargaining agreement between players and owners expires this year, the 15 biggest-market teams no longer will be eligible for revenue sharing. The A’s are on the list to get shut out.

Don’t get excited yet, A’s fans. As the agreement works now, the A’s would remain eligible for revenue sharing as long as their ballpark situation remains in limbo.

But! When a new CBA is finalized, it’s possible that the A’s exemption from the Fifteen Rule could be erased, or gradually phased out. The A’s gravy train would be derailed. If that happens, Fisher-Wolff might be tempted to sell.

Or maybe not.

In an email exchange with Wolff on Wednesday, he told me, “We are not sellers now or in the future. Our work is always shared with MLB and any party that we deem applicable to contributing to our work. I hope the fans know that we are focused on the city of Oakland ...”

Wolff also wrote, “The work on a city of Oakland location is extensive and constant,” but he declined to elaborate.

I responded that I don’t believe that A’s fans know team ownership is focused on Oakland, because fans have no recent news on ballpark plans, negotiations or discussions. To the outside world, it looks like nothing is happening, except that the A’s keep making money while Billy Beane and his front-office crew keep playing at what Beane once described as “the $5 (blackjack) table.”

The Oakland sports-venue dance is as clumsy and painful to watch as Quasimodo at the senior prom. The A’s and Raiders, who apparently do not communicate or coordinate their respective efforts to build venues in Oakland, keep waiting for the other team to leave town so they can gain negotiating leverage with the city.

But nobody budges. All talk, no rock.

I promised A’s fans this column would contain something to dream about. Maybe I oversold it. There’s only a glimmer of reality behind this dream, but what else do you have right now?

Scott Ostler is a San Francisco Chronicle columnist. Email: sostler@sfchronicle.com Twitter: @scottostler