Acquiring Dan Haren from the A's gives the Diamondbacks the No. 2 starter they thought they were getting last winter when they traded for Randy Johnson, and Arizona is now much better prepared to live without the Big Unit's services in 2008. Meanwhile, Oakland gets a headstart on its rebuilding process, including one high-ceiling hitting prospect and some interesting left-handed arms.

Haren is coming off a career year that saw him start the All-Star Game for the American League with a 2.30 ERA up to that point, but after the break he was more like he'd been in the previous two years, a very durable strike-thrower with a three-pitch arsenal but no knockout pitch. His four-seamer is 89-93 mph with just a little arm-side run, but he commands it well. His best secondary pitch is his splitter, 82-85 mph with good bottom, and it's particularly effective against left-handed hitters, which is important for Haren because he doesn't pitch well to his glove side. His curveball, 78-81 mph, is fringe-average with a somewhat soft break. He has good tempo and pounds the strike zone, and he's been very durable, making every start since he was traded to Oakland in the Mark Mulder heist before the 2005 season.

Haren will move from a great pitchers' park to a good hitters' park, so the home run tendency he shed in 2007 could return in 2008. Arizona also got a fringe bullpen arm in Connor Robertson, whom it could have had for free in October when Oakland placed him on outright waivers.

The two prizes in the deal for Oakland are outfielder Carlos Gonzalez and left-handed starter Brett Anderson. Gonzalez is a high-ceiling prospect whose tools are average or better across the board, but his game is undisciplined and he's a high-risk proposition. He has a clean, simple swing and takes a short path to the ball, and he shows above-average power in batting practice that hasn't fully translated into games yet. His approach, however, is poor; he doesn't recognize offspeed pitches or adjust his approach by the situation, and while he's young (he just turned 22 in October), he's getting to the point where he should be making at least some of these adjustments. He has enough arm to play right field, but he returned to center for most of the last month of the 2007 season and has star potential if he can play there. His offensive upside would be something like .300/.340/.500, although the power output might be dampened by Oakland's big park and the two other pitchers' parks in the American League West.

Anderson, the son of Oklahoma State baseball coach Frank Anderson, is a pitchability lefty who already has an above-average curveball with good depth and an average fastball in the 87-89 mph range with very good sink. His best attributes, however, are his control and his feel for pitching, both of which are unusually good for a teenaged pitcher (he will turn 20 in February) in pro ball. There's always some concern about young pitchers who've thrown a lot of breaking balls (Anderson also throws a slider, but it's inconsistent), and Anderson does throw across his body a bit. He missed most of last August after being involved in a late-July car accident, although one report on minorleaguebaseball.com said he was out with a "tender arm." He's a very good prospect, but with some red flags typical of teenaged pitchers.

Oakland also picked up two candidates for its 2008 rotation in lefties Dana Eveland and Greg Smith. Eveland missed most of 2007 with a strained finger on his pitching hand, but also struggled to keep his weight in check and did not pitch well in two cups of coffee with Arizona. When healthy and relatively trim, Eveland has an average fastball and a plus slider, with a spiking curveball that fools minor-league hitters, something major-league hitters will probably lay off. Smith has a solid-average fastball and a 12-to-6 curve that is his out pitch; he has good control but tends to throw across his body when he needs to pitch to his glove side. His third pitch, his changeup, is below average and he'll need to improve it (or pick up a splitter) to get right-handed hitters out in the majors.

Two minor-league bats rounded out the deal. Oakland got the same Chris Carter that Arizona acquired from the White Sox in a trade in early December; he's a very young, defensively-challenged slugger with big raw power now and the potential to hit 30-plus homers in the majors if he can do enough other things to make it there. Aaron Cunningham projects as a very good fourth outfielder who can play all three outfield spots and who can be a pinch-runner off the bench, but he isn't quite good enough in center to start there and doesn't have the power to profile in a corner spot.