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7/29/2014 4:01 P.M. ET

Five contenders with young talent to trade

Pirates, Dodgers lead clubs that could be active with prospects at Trade Deadline

The non-waiver Trade Deadline isn't until Thursday, but some contenders already have decided to avoid doing their shopping at the last minute.

On July 5, the Athletics packaged one of the game's top prospects (shortstop Addison Russell) and their 2013 first-round Draft pick (outfielder Billy McKinney) with Dan Straily and a player to be named to get Jeff Samardzija and Jason Hammel from the Cubs. When all is said and done, Samardzija could be the best big leaguer and Russell could be the best prospect to change addresses this summer.

Two weeks later, the Angels decided they needed to upgrade at closer, and they didn't let having one of baseball's thinner farm systems stop them. They gave up four of their best prospects -- shortstop Jose Rondon, second baseman Taylor Lindsey and right-handers R.J. Alvarez and Elliot Morris -- to pry Huston Street and Minor League righty Trevor Gott from the Padres.

The Tigers bolstered their bullpen last week with the addition of Joakim Soria, at the cost of a pair of promising young right-handed hurlers, Jake Thompson and Corey Knebel, whom they sent to Texas for the All-Star reliever. And on Saturday, with the status of starter Matt Cain uncertain, the Giants dealt their second- and 11th-ranked prospects, Edwin Escobar and Heath Hembree, to Boston for veteran righty Jake Peavy.

And there could be plenty more wheeling and dealing before the clock strikes 4 p.m. ET on Thursday. Twenty-one of MLB's 30 teams led playoff races or were within six games of a postseason berth before play started on Tuesday, and many of them are in position to make moves to boost their chances. That being the case, here are the five contenders best positioned from a talent standpoint to make a significant trade:

1. Pirates

Even after promoting überprospect Gregory Polanco to the Majors and having right-hander Jameson Taillon sidelined by Tommy John elbow surgery, Pittsburgh still has one of the top farm systems in baseball. The Pirates' big league outfield is stacked, and even if Polanco were untouchable, they have several quality outfield prospects to deal in Josh Bell, Austin Meadows and Harold Ramirez.

Teams don't like to deal potential front-line starting pitchers, but Pittsburgh could part with Taillon (who would be an interesting buy-low investment) or right-hander Tyler Glasnow and hold on to the other. Righty Nick Kingham is another possibility, while shortstop Alen Hanson and catcher Reese McGuire are valuable up-the-middle commodities. No contender can match the Bucs' combination of prospect quality and quantity.

2. Dodgers

With its financial might and three of baseball's top prospects, Los Angeles has the wherewithal to acquire anyone who comes on the trade market. Whether the Dodgers would significantly add to what was a record $235 million Opening Day payroll or would actually part with shortstop Corey Seager, left-hander Julio Urias or outfielder Joc Pederson is another question.

Pederson is the most expendable, because the Dodgers already have more outfielders than they can play at the big league level. They also have plenty of pitching depth behind Urias, including former first-rounders Chris Anderson and Zach Lee, to help facilitate a deal.

3. Cardinals

Outfielder Oscar Taveras is the best pure hitting prospect in the Minors. If St. Louis doesn't want to trade him, it could install Taveras in its Major League lineup and make Matt Adams or Allen Craig expendable. Similarly, the Cardinals could deal rookie second baseman Kolten Wong and shift Matt Carpenter back to second and Craig back to third, though they would take a defensive hit in the process.

In addition to Taveras, St. Louis has three other nearly-ready outfielders to spare in Stephen Piscotty, James Ramsey and Randal Grichuk. The Cards never seem to run out of pitching, and lefties Rob Kaminsky and Marco Gonzales and righty Alexander Reyes all would command attention on the trade market.

4. Mariners

Right-hander Taijuan Walker and lefty James Paxton have had shoulder issues, but both of their names came up when Seattle inquired about obtaining David Price from the Rays. The Mariners also have several infield options, which could make third baseman D.J. Peterson and shortstop Chris Taylor available, and they have some interesting high-risk/high-reward types such as outfielders Gabriel Guerrero and Austin Wilson.

5. Royals

If Kansas City wants to make a bold push for its first playoff appearance since winning the 1985 World Series, it could cash in its farm system. Shortstop Raul Adalberto Mondesi could be redundant with Alcides Escobar in the big leagues. Right-hander Kyle Zimmer and lefty Sean Manaea don't have the cleanest medical histories, but they have huge upsides, and third baseman Hunter Dozier and righty Miguel Almonte are attractive prospects as well.

Also keep an eye on the Nationals and Reds. They aren't as deep in young talent as the five organizations mentioned above, but they each have Futures Gamers (right-hander Lucas Giolito and outfielder Michael Taylor for Washington, righty Robert Stephenson and outfielder Jesse Winker for Cincinnati) and an upper-level righty (A.J. Cole for the Nats, Michael Lorenzen for the Reds) who would make for a nice package. Some scouts believe Giolito is baseball's best pitching prospect, and Stephenson isn't far behind him.

Jim Callis is a reporter for MLB.com and writes a blog, Callis' Corner. Follow @jimcallisMLB on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.