Even if Jason Hammel hadn't had one of the worst four-start stretches of his career, Jon Lester still would be a significant upgrade over him. And the A's needed more help in their rotation, which has been around the league median so far this year, than they needed Cespedes in their lineup, which has been among the AL's most productive thanks in large part to smart, cost-effective platoon pairings. Oakland's rotation to date has relied on Jesse Chavez, a career reliever who's already 30 innings over his professional single-season high, and Tom Milone, who's struggled away from home because he's an extreme fly ball guy with a below-average fastball. (Milone is now a Twin, traded for Sam Fuld in a swap of last-roster-spot guys.) Adding Lester and Jeff Samardzija to the rotation this month gives the A's high-impact starters for the playoffs and significant bulk innings to ward off September fatigue from pitchers such as Chavez or Drew Pomeranz, who haven't handled these workloads before. It makes the A's a win or two better the rest of the way, and it also sets them up far better for October.
They also added Jonny Gomes -- whose one major baseball skill is smacking around left-handed pitching -- to an outfield platoon mix that also considers who's on the mound for Oakland (since Fuld is a better defender than Gomes).
The Red Sox likely could have dealt Lester for prospects, but they used him for a one-year solution (or more, if they extend him) to their corner-outfield issues instead. Cespedes has huge raw power and is likely to become a 30-plus home run hitter now that he's away from Oakland and its pitcher-friendly road schedule. As good as Cespedes can be, however, he's not an elite offensive player because he doesn't get on base -- .303 this year, .294 last year and worse away from Oakland in both seasons. He's a four- to five-win player overall because he's become an excellent defender in left who's capable of handling center (if needed) but unlikely to do so with the Red Sox's depth at that position, which only grows after the deal that sent John Lackey to the Cardinals. The acquisition could also make Shane Victorino expendable when healthy; Cespedes could play right, and the Sox have more infield prospects than they can play and could move someone such as Garin Cecchini to left.
Cespedes will be a free agent after 2015 because, like most pro players from Cuba, Japan and Korea, he has a clause in his contract that forces his employers to non-tender him before he reaches six years of service, which also means he can't bring a compensatory draft pick back. That makes this a clear move for Boston to try to win again in 2015, which makes sense given the lineup and the high upsides of young players such as Cecchini, Xander Bogaerts, Mookie Betts and Blake Swihart. But it also leaves them without a No. 1 starter -- someone likely to provide 200 innings and worth five to six wins above replacement a year, a pace Lester was going to surpass this year. Perhaps they can use this prospect depth to make a run at someone such as David Price, who's also under control for next year?
With Lackey also on the move, this deal doesn't leave a ton on the trade market for teams looking for a starter this year, assuming Price is unlikely to move today. But if the Rockies change their stance on Jorge de la Rosa, he'd be the most attractive rental starter available: a lefty with power stuff who should play anywhere and a track record of pitching well in an adverse environment in Colorado. I've banged that drum often this summer, but I think trading de la Rosa would set the Rockies up well to contend when some of the prospect depth in their system, led by Jonathan Gray, starts to arrive next year.