Now that the baseball world has departed Miami following a wildly successful All-Star week, the real derby is ready to begin: the non-waiver Trade Deadline.

Teams around MLB have less than three weeks to decide how to shape their rosters for the rest of the season, whether it's buying a piece or two for a pennant run or selling assets with an eye toward the future.

• Standings

Given that 12 of the 15 teams in the American League are within four games of a postseason spot, the crowded playoff picture has muddled the Deadline landscape. The National League is a lot easier to project, as the five teams currently in postseason position all have a cushion of at least 5 1/2 games -- and the other 10 teams have sub-.500 records.

Teams like the A's are already looking to sell, dangling controllable starter Sonny Gray. But while he may appear to be the best available pitcher on the market, now that Jose Quintana is headed to the Cubs -- that might not be the case two weeks from now.

"If Kansas City goes out and loses 10 games, maybe Jason Vargas becomes available," one AL general manager said. "Right now, they're planning on him not being available."

Ditto for other middling AL hopefuls including Toronto (Marco Estrada? J.A. Happ?), Minnesota (Ervin Santana?) and Texas (Yu Darvish? Andrew Cashner?), all of whom are one good winning streak -- or losing streak -- away from declaring their Deadline intentions.

"It's not only figuring out where your team fits, but also having more clarity of who is available and who isn't," the GM said.

With that in mind, teams could be hesitant to pull the trigger on a deal for a starter such as Gray until they have a better idea of who else might become available.

Two years ago, the Astros traded for Scott Kazmir on July 23, believing the left-hander would bolster their rotation for the stretch run. Less than a week later, David Price became available after the Tigers lost five of six games. Price was traded to Toronto, which went on an epic 42-14 run thanks largely to its new southpaw, who went 8-1 with a 1.95 ERA in his first 10 starts with the Blue Jays.

"I'm guessing most things will happen closer to the Deadline, like last year was," the GM said. "Two years ago, there was a bit of a flurry and some executives have even suggested they regretted the flurry, because after initiating early, certain players shook free. With how muddy the water is now -- especially in the American League Wild Card -- there are going to be some players available that aren't necessarily available today."

According to a second AL GM, the names that have been thrown around during discussions with other teams have been the usual suspects. That could change as the Deadline gets closer.

"Those surprises are going to come from teams that haven't declared themselves yet," the GM said. "That's when it gets interesting."

For instance, is Justin Verlander on the market or not? The second GM said that while the Tigers aren't actively shopping the former AL MVP Award and AL Cy Young Award winner, the perception is that Detroit "could be talked into moving him" before the Deadline if the right package came along.

The relief market is already loaded with available talent, with closers Player Page for David Robertson, Addison Reed and A.J. Ramos as well as All-Star setup men Brad Hand and Pat Neshek representing five of the dozen or so bullpen arms that appear to be for sale. Expect a number of relievers to be moved between now and July 31.

As for hitters, the biggest names believed to be on the market are J.D. Martinez (Tigers) and Yonder Alonso (A's), both of whom are headed for free agency at the end of the season. That could hinder the price tags for their current teams, as many executives will be hesitant to pay a premium for short-term players, especially in the ultra-competitive AL.

"Each year, it seems less GMs are willing to make a big splash for two-month rentals unless they're elite," the first GM said. "Andrew Miller was a big splash, but there were years of control."

To that end, some teams that are looking ahead to 2018 and beyond won't be so quick to trade those young, controllable -- and, in many cases, inexpensive -- assets away.

The Marlins, for example, will look to trade the likes of Ramos, David Phelps, Martin Prado and possibly Dee Gordon in the coming weeks. Justin Bour, Christian Yelich and Marcell Ozuna, on the other hand, are unlikely to be moved no matter how many times their names appear in trade rumors.

"It makes no sense," one NL executive said. "If they're looking to contend in the next year or two, why would they trade the young core?"

So who will be the biggest names to move in the next 19 days? Until the standings begin to paint a clearer picture, nobody knows for sure.

Even those on the inside seem baffled by what the market will ultimately look like. As the first AL GM said, "Your guess is as good as mine."