The following is a look at the impacts of some of the most important offseason trades (teams that made the acquisition in parentheses).
Tyler Chatwood (Rockies) for Chris Iannetta (Angels): Iannetta was brought in to handle the Angels' elite pitching staff but has since been sidelined by a wrist injury that could keep him out six to eight weeks. He was relatively productive at the plate, posting a .312 on-base percentage with a little bit of power (three homers, nine RBIs). Chatwood appeared in four April games with the Rockies, allowing five earned runs in eight innings of relief before being sent to Triple-A to work as a starter.
Jonathan Sanchez and Ryan Verdugo (Royals) for Melky Cabrera (Giants): The Royals got to sell high on Cabrera after a banner campaign in 2011, but he's kept it up, batting .338 with two homers, 14 RBIs and a .876 OPS. Sanchez, meanwhile, hasn't won since his season debut and has an ERA of 6.75.
Angel Pagan (Giants) for Andres Torres and Ramon Ramirez (Mets): Pagan has also been a part of San Francisco's reinvigorated outfield, batting .277 with nine RBIs and six stolen bases primarily out of the leadoff spot. Torres' .393 on-base percentage has been his calling card, and Ramirez has a 4.66 ERA through 19 1/3 innings of relief work.
Huston Street (Padres) for Nick Schmidt (Rockies): The Padres needed a replacement after the departure of Heath Bell, and they got it in Street, whose ERA had climbed over his previous two seasons in the Mile High City. He on the disabled list with a strained right lat muscle, but he's a perfect 4-for-4 in save opportunities with a sterling 0.93 ERA in the pitcher-friendly confines of Petco Park.
Tyler Colvin and DJ LeMahieu (Rockies) for Casey Weathers and Ian Stewart (Cubs): The Rockies finally parted ways with Stewart after waiting for him to be the consistent offensive force at third base they hoped he'd be. He still hasn't hit for average (.203 with the Cubs) but has a little bit of pop (four homers and 12 RBIs). Colvin is pushing Dexter Fowler for playing time, with a .311 batting average and .869 OPS through 27 games.
Jarrod Parker, Collin Cowgill and Ryan Cook (A's) for Trevor Cahill and Craig Breslow (D-backs): Parker has done well in the A's rotation (1-1, 2.10 ERA through four starts), and Cook has been nearly flawless out of the bullpen (no earned runs in 17 2/3 innings). Cahill, the biggest piece of the deal for Arizona, is 2-4, and his strikeouts per nine innings have dropped, from 6.4 to 5.1.
Casey McGehee (Pirates) for Jose Veras (Brewers): The Brewers didn't miss McGehee long, trading him on Dec. 12 and signing third baseman Aramis Ramirez a day later. McGehee has hardly produced in Pittsburgh, batting .218 with four RBIs and no homers, whereas Ramirez has filled in admirably. Veras was strong in Spring Training but has struggled to a 6.75 ERA through 16 innings.
Mat Latos (Reds) for Yonder Alonso, Edinson Volquez, Yasmani Grandal and Brad Boxberger (Padres): Latos admits to feeling the responsibility of being the key piece of a deal for four players, and he has scuffled to a 2-2 record with a 4.54 ERA in seven starts.
"Who's to say I am worth four players? But who is to say that I am not?" Latos said earlier in the year. "Just to look back at the trade, you say, 'Wow, I just got traded for four guys.' Obviously, I meant a lot to them. It's a blessing to have it happen."
Gonzalez and Robert Gilliam (Nationals) for A.J. Cole, Derek Norris, Brad Peacock and Tom Milone (A's): Gonzalez had been good with the A's for three seasons but he's been great with the Nats, helping lead one of baseball's best rotations. Milone is the only A's player in the deal to see the big leagues, posting a 5-2 record and 3.92 ERA through seven starts.
Ryan Sweeney and Bailey (Red Sox) for Josh Reddick, Josh Head and Raul Alcantara (A's): Bailey was the main piece for the Red Sox in this deal, but it's been Sweeney who's seen the field most, as Bailey is on the 60-day disabled list with a thumb injury. Meanwhile, Reddick has been one of Oakland's most productive players, batting .289 with 20 RBIs and a team-best nine homers.
Chris Volstad (Cubs) for Carlos Zambrano and cash (Marlins): The Cubs had reached the end of the road with Zambrano, who has benefited from a change of scenery under manager Ozzie Guillen in Miami (1.88 ERA, 7.3 strikeouts per nine). Volstad has been dreadful in Chicago and is winless (0-5) with a 6.92 ERA through seven starts.
Hector Noesi and Jesus Montero (Mariners) for Pineda and Jose Campos (Yankees): The Yankees are stinging from this one, as Montero leads the Mariners in homers, with five, and has 17 RBIs. Noesi has been lackluster in the Seattle rotation, but the Yankees have nothing to show so far for the deal, as Pineda's shoulder injury has kept him from making his New York debut, which won't happen until next year.
Josh Outman and Guillermo Moscoso (Rockies) for Seth Smith (A's): Outman and Moscoso competed for spots on the Rockies' big league roster in Spring Training but fell short. Both were eventually presented with opportunities during the young season and struggled mightily. Smith continues to fight for at-bats. He's batting .253 with three homers and 11 RBIs.
Clayton Mortensen (Red Sox) for Marco Scutaro (Rockies): Mortensen was superb in his stint out of the Boston bullpen (0.96 ERA through 9 1/3 innings) but was sent down recently because he has options. Scutaro, one of many new faces in Colorado, ranks second on the club in runs (20), but has shown little production in any other facet.
Matt Lindstrom and Hammel (Orioles) for Jeremy Guthrie (Rockies): The Rockies were looking for a new ace after dealing Ubaldo Jimenez last year, and Guthrie became that man. But he's spent time on the disabled list (and otherwise has a 5.92 ERA through four starts), whereas Hammel has been one of baseball's most surprising bright spots (4-1, 2.68 ERA).
A.J. Burnett (Pirates) for Exicardo Cayones and Diego Moreno (Yankees): It was about time the Yankees parted ways with Burnett, who just never found his stride in the Bronx. Burnett sustained a freak injury in Spring Training that pushed back his Pirates debut. He was superb on April 21 in his first start but hit a rough patch shortly thereafter, though he has been much better in his past two starts (16 innings, four earned runs combined).