Its safe to say things haven't gone as planned post world series for the Red Sox. They're currently fading post- All Star Break and appear to be sellers as the deadline approaches. And its safe to say that the biggest trade chip the Red Sox have is SP Jon Lester.
A pending free agent, things haven't gone all that smoothly in terms of negotiations between the Sox and Lester. In spring training, it was leaked that the Sox offered an initial 4yr/$70M extension, well south of what Lester will receive on the open market. Right now its looking like Lester could approach Cole Hamels territory, 7yr/$153M. While there's been talks that he's open to a "hometown discount", the truth is, its still going to take quite a bit to retain Lester. There's been confusion abound as to whether or not Lester is open to negotiating during the season. Both sides have gone back and forth, but are currently in a state of waiting until the offseason, which Lester reportedly prefers. Honest to say, confidence that the front office will give Lester the contract that it'll require isn't that high. So if the Sox don't end up resigning him, they can attach a qualifying offer (which he'll certainly decline) and get a compensatory draft pick, or look to capitalize on the high price for pitchers for this year's trade market.
Lester's value is probably at an all-time high right now. He's pitching like an ace (that's a debate saved for later). Thus far, he has a 2.52 ERA, 2.0BB/9, 9.4K/9 and his FIP matches his ERA at 2.63. He's been dominant in the postseason as well throughout his career, with a 2.11 ERA. The Rays' David Price had been a sought after trade chip, but with a recent surge from the Rays, its possible they'll wait until the offseason to deal Price, making Lester the most sought after SP on the market right now.
For one, the Sox have the pitching depth in their system. First off, there's the pair of pitchers they received in the Adrian Gonzalez deal, Rubby De La Rosa (currently in the rotation), and Allen Webster. Then there's the rising and dominant Henry Owens, Anthony Ranaudo (who's having a dominant season in Pawtucket), Brandon Workman (who's made an impact in Boston over the past year), Matt Barnes and last year's first founder Trey Ball. That's on top of the pair of pitchers that Boston received recently in the Jake Peavy deal to the Giants, Edwin Escobar and Heath Hembree (a minor league RP/potential closer). Its safe to say that Boston's system is rich in pitching and prepared for the future, allowing them to capitalize on Lester's value.
The Sox system may be rich in pitching, but has been weak on power. Will Middlebrooks has bounced around, and is looking to regain his form following an injury, while Jackie Bradley Jr has played terrific defense in CF, but has had his struggles during the season. You frequently see Sox fans pining after a corner OF like Giancarlo Stanton or Carlos Gonzalez (of the Marlins and Rockies, respectively). The Sox could find that outfielder with two possible suitors for Lester, the Cardinals, and Dodgers.
While the Cardinals could chip in some young pitchers, any Lester deal would certainly have to include Oscar Taveras. Prior to the season, Taveras was a consensus #3 prospect (according to Baseball America, Baseball Prospectus and MLB.com). Taveras has had his struggles this year with the Cardinals (28 Games, 1HR/6RBI, .214/.247/.286 line). However, he's had a good track record in AAA this year (8HR/49RBI in 62 games, with a .318/.370/.502 line for a .872 OPS). Taveras missed the second half of last year with an ankle injury, resulting in his slow start to this year. But the consensus is that Taveras has the potential, being compared to the likes of Valdimir Guerrero .
The Dodgers on the other-hand have Joc Pederson, who while has played the majority of his time in CF in the minors, he's also seen plenty of time in LF. Pederson has the potential to be a 20/20 player (HR/SB), possibly even 30/30. Right now in AAA, he has 21HR/53RBI with 25SB, with a .327/.458/.594 line and a 1.053OPS. While he's playing in the hitter friendnly Pacific Coast League, Pederson has been consistent over the past few years. He's a top 50 prospect (#34 Baseball America, #36 MLB.com, while Baseball Prospectus has him at #50).
Another target could be the Pittsburgh Pirates. They have a number of blocked OF prospects, like Josh Bell, Austin Meadows and Harold Ramirez. Granted, these prospects are about 1 to 2 years away, but the Pirates also have pitching prospects like Tyler Glasnow and Nick Kingham. Josh Bell has recently debuted with AA Altoona, but this year with Bradenton, he hit for a .335/.384/.502 line with 9HRs and 53RBI. Meadows has dealt with injuries, but was the Pirates 2013 1st round selection. I'm not sure the Pirates would be willing to part with both Glasnow (1.74 ERA with Bradenton in 17 starts) and Bell, but Kingham also has potential (3.04 era split between Altoona and Indianapolis in 20 starts). The Pirates have a lot of good, but tradeable prospects.