(Sports Network) - The Washington Nationals are expected to get a big lift in their lineup tonight, when they open a three-game series against the San Francisco Giants at AT&T Park.

The Nationals have been without third baseman Ryan Zimmerman since late May because of a small tear in his left shoulder. Zimmerman, who is hitting .257 with eight homers and 27 RBI, did not undergo surgery and opted for rest. Washington went 16-32 with Zimmerman on the disabled list, but expects its standout slugger back in action tonight.

Washington is last in the NL East standings, but has won two in a row since losing three straight. It won the last two contests of a three-game series at Atlanta's Turner Field to kick off a nine-game trek, including Sunday's 15-6 pounding of the Braves in the series finale.

Willie Harris homered and drove in five runs to lead the deluge, while Felipe Lopez finished 3-for-4 with three RBI and three runs scored. Austin Kearns had a big day for the Nats as well, collecting three hits -- including a homer -- two runs batted in and a franchise-tying five runs scored. Jesus Flores chipped in a career-high five hits with two RBI and two runs scored.

Washington starter Odalis Perez earned his first win since May 28, allowing five runs on nine hits through five frames while fanning four batters and walking two.

The Nationals are 2-1 on this trip and 18-31 away from D.C. this season.

Jason Bergmann gets the nod for Washington on Tuesday and hasn't won since hurling seven shutout innings against the New York Mets on May 15. He is 0-5 in 11 trips to the mound since then, while sporting a 1-6 record and a 4.03 ERA through 15 total games (13 starts) this season.

In his previous outing Friday at Atlanta, Bergmann gave up one run in two innings for a no-decision in a 7-6 Washington loss.

The righty is 0-1 with a 9.00 ERA in two career games (1 start) against the Giants. He faced San Francisco in a 10-1 loss on June 6 of this season, yielding eight runs -- five earned -- and 10 hits in just three innings of work.

The Giants were just swept in three games at home by the Milwaukee Brewers and suffered their ninth setback in 10 tries with Sunday's 7-4 loss.

Starting pitcher Tim Lincecum, who was back after a bout with the flu that caused him to miss the All-Star game, showed no ill effects but was hurt by two homers as he gave up five runs on six hits and four walks over six-plus frames. The righty fanned eight batters in losing for the second time in his last three starts after starting the year 10-1.

Jose Castillo had two hits, two RBI and a run scored for the Giants, who fell to 0-3 on a nine-game homestand and 17-31 by the Bay this season. Aaron Rowand knocked in two runs with a double, while Emmanuel Burriss added two hits and scored a run in a losing cause.

Giants starter Barry Zito will try to bounce back from a subpar outing when he takes the ball on Tuesday. Zito did not factor in the outcome of a 7-3 loss against the New York Mets his last time out on July 10. He allowed three runs -- two earned -- on four hits in five innings of work.

Zito, who is 2-1 in his last four outings, sports a 4-12 mark with a 5.62 earned run average in 19 trips to the rubber in 2008. The left-hander and 2002 AL Cy Young Award winner defeated Washington on June 8 despite permitting three runs and seven hits in five frames of a 6-3 victory.

Zito is 1-1 with a 3.91 ERA in four career starts against the Nats.

San Francisco swept a four-game set against Washington in D.C. from June 6-9 of this season. The Nationals were 9-4 in the last 13 games of this series before losing the last four matchups with the Giants.