The Arizona Diamondbacks made a major move to shore up their ailing bullpen on Tuesday by acquiring reliever Jon Rauch from the Washington Nationals for infield prospect Emilio Bonifacio.

Rauch was 4-2 with 17 saves in 22 chances and a 2.98 ERA for the Nationals. Bonifacio entered the season as Arizona's No. 6 prospect, according to Baseball America.

Astros acquire Wolf in trade with Padres: The Houston Astros acquired pitcher Randy Wolf from San Diego in exchange for minor leaguer Chad Reineke.

Wolf, an NL All-Star in 2003, is 6-10 with a 4.74 ERA in 21 starts for the Padres this season. He will start for Houston on Sunday at Milwaukee, the Astros said.

Giants activate Roberts: The San Francisco Giants activated outfielder Dave Roberts from the disabled list following a long recovery from left knee surgery.

The 36-year-old Roberts had cartilage cleaned out from behind his left kneecap caused by arthritis and wear and tear. Roberts had been on a rehabilitation assignment with Triple-A Fresno before being activated.

Reds' Fogg hit in mouth during batting practice: Cincinnati Reds right-hander Josh Fogg was hit in the mouth by a ball during batting practice and was taken to a medical center where he got 30 stitches for a split upper lip.

A ball hit by Joey Votto smacked Fogg, who was in the outfield during batting practice. Fogg left the field with the assistance of a trainer who held a towel in front of his face.

Fogg is scheduled to start Friday against Colorado.

Nationals' Guzman receives two-year contract extension: Washington shortstop Cristian Guzman agreed to terms on a two-year contract extension that takes him through the 2010 season.

The 30-year-old All-Star entered the series opener at San Francisco batting .310 with five home runs, 34 RBIs, 56 runs scored, three triples and 26 doubles in a team-high 96 games this season.

Pena has surgery on left shoulder: The Nationals say outfielder Wily Mo Pena has had surgery on his left shoulder and will miss the remainder of the season.

The team says the surgery was performed in Cincinnati to repair a partial tear of Pena's rotator cuff and a tear of his labrum.

Bedard gets MRI on left shoulder: Injured Mariners starter Erik Bedard got an MRI on his left shoulder, but team physicians found no new causes for the nagging tightness and soreness the lefty is experiencing.

A-Rod signs with William Morris Agency: Alex Rodriguez signed another big-league contract, joining the William Morris Agency in an attempt to extend his brand beyond the baseball diamond.

The New York Yankees slugger signed with the powerhouse talent agency in Beverly Hills and becomes part of a client list that includes some of the biggest names in sports, entertainment and business.