The drumroll is building toward Sunday's 4 p.m. ET non-waiver Trade Deadline. It began appropriately enough in Cleveland, where longtime fan John Adams has been striking his drum for 30 years and where the Indians struck a Thursday deal with the Cubs for outfielder Kosuke Fukudome.

And it could reach ear-assaulting proportions before the weekend runs out, as teams hustle to fill their stretch-drive shopping carts.

Blinking on the shelf are outfielders B.J. Upton and Hunter Pence; front-of-the-rotation arms Ubaldo Jimenez, Hiroki Kuroda, Erik Bedard and Wandy Rodriguez; fireman hoses Heath Bell, Grant Balfour and Mike Adams; and the versatility of Jamey Carroll and Ty Wigginton.

Trade Include

Those principals really are available -- if their teams' hefty prices are met. There's little bait-and-switch in this marketplace: Already moved have been such advertised names as Carlos Beltran (Mets to Giants), Colby Rasmus (Cardinals to Blue Jays) and Edwin Jackson (White Sox to Cardinals, via Blue Jays).

Next headliner to go? A "sixPence" for your thoughts: The Houston outfielder has quickly taken Beltran's place as the most-desired impact bat. The Astros are actively pitting a minimum of six teams against each other in the bidding, most prominent among them the Phillies, Red Sox and Braves -- whose general managers must decide where to hold the line.

Such lightbulbs blink on and off in the minds of all GMs: "How much of tomorrow's talent and of today's dollars do I leverage to turbo-up for the next two -- hopefully, three -- months?"

Dwindling hours to make those calls. While certainly not a reliable precedent, it is interesting to note that the last Trade Deadline countdown wrapped around a weekend -- in 2005 -- passed quite quietly. Only 10 low-key trades went down in that Friday-to-Sunday period, with Chan Ho Park and Randy Winn the biggest names involved. Contributing to that may have been an average division lead of five-plus games into that weekend.

Heightening the suspense now: Entering this weekend, neck-and-neck races in five of the six divisions, and the exception is the National League East, where the Phillies have a five-game lead over Atlanta but are always in a shopping mode with an eye on the postseason, anyway.

As usual, the Red Sox and Yankees are in the eye of the storm. The American League East rivals operate according to Newtown's law: For every action, there is an equal and opposite reaction.

This time, both teams hunt the same quarry: Starting pitching. Boston is very concerned about the prognosis for Clay Buchholz's back, and New York is unconvinced about Phil Hughes' recovery.

That pitching market's spotlight will be trained Friday night on Seattle's Safeco Field -- where left-hander Erik Bedard will be making his first start off a month's absence with a sprained left knee. The left-hander's recovery will be intensely scouted by several teams who consider him the highest-end available pitcher. Bedard's dispensation will trickle down to other starters on the counter: Jimenez, who goes Saturday in San Diego, Baltimore's Jeremy Guthrie, Rodriguez and Kuroda.

The East jousters always rate above-the-title billing, but a comparable AL brouhaha brews between West front-runners Texas and Los Angeles, which share an Achilles' heel: their bullpens. Both teams enlist headlining rotations, but the Angels top the Majors with 11 walk-off defeats and the AL with 18 blown saves, and the Rangers' collective relief ERA (4.48) ranks 26th.

Texas clearly has the superlative offense, an area the Angels have targeted for improvement for more than a year since Kendrys Morales totaled his left ankle on May 29, 2010. But GM Tony Reagins' hands are tied by ownership's reluctance to give up prospects or take on significant payroll.

The biggest stash of available relievers is in Oakland -- Balfour, Craig Breslow, Brian Fuentes, Michael Wuertz, perhaps even Andrew Bailey -- but Athletics GM Billy Beane's dissatisfaction with what he's been hearing apparently leaves the Padres as the liveliest source.

"In respect for [manager] Bob Melvin, we're not going to strip-mine things for two months for players of no consequence," Beane told the San Francisco Chronicle.

His San Diego counterpart, Jed Hoyer, remains ready to move Bell; setup man Adams is in even more demand and would fetch a higher return.

The Phillies and Braves, both of whom were initially after Beltran, will continue to square off in their quest for a right-handed-hitting outfielder. Atlanta's need is more acute, with Jordan Schafer, plus catcher Brian McCann, on the disabled list, and Chipper Jones still beset by leg problems.

Topping the Braves' wish list now is Pence, the 28-year-old Houston right fielder also targeted by the Red Sox and the Tigers. Tampa Bay is more receptive to moving Upton, but his market won't pick up until Pence is off the board. Ryan Ludwick (Padres) and Carlos Quentin (White Sox) -- and the Pirates and the Rangers -- are other components of the outfield market.

To illustrate the dynamics of this weekend, the NL Central-leading Brewers reacted quickly to the loss of All-Star Rickie Weeks to a sprained left ankle: Milwaukee, which had already been shopping for a left-handed specialist for its bullpen, promptly reacquired veteran infielder Felipe Lopez -- he spent 2009 with the Brewers -- from Tampa Bay on Thursday.

In the same situation a year ago, Philadelphia didn't overreact when Chase Utley went out with a sprained right thumb on June 28 and remained out until Aug. 17; the Phillies stayed in-house, with veteran journeyman Wilson Valdez as the primary in the second-base shuffle, and went 26-17 in Utley's absence.