Jeff Samardzija will start for the Cubs for the first time since September 2010. He was 8-4 with a 2.97 ERA in 2011, used exclusively out of the bullpen in 75 appearances. He'll be up against Washington right-hander Jordan Zimmermann, who is off the innings limit that held him to 161 1/3 frames last season as he worked his way back from Tommy John surgery.
The first pitch Sunday at Wrigley Field is slated for 2:20 p.m. ET. The Nationals are looking to leave Chicago with a sweep after scoring five runs in the eighth inning Saturday to take the second game of the series, 7-4.
Samardzija has a 2.08 career ERA against the Nationals, and is coming off a 3-1 mark with a 4.50 ERA in five games (four starts) in Spring Training.
"I preached all spring getting off to a quick start as a team, so I can't say it's not the same for myself," Samardzija said. "It's important to do what you need to do to set the tone for the rest of the season."
Zimmermann, meanwhile, is coming off an 8-11 campaign after his 2010 was shortened by injury. He was 1-2 with a 3.38 ERA in Spring Training this year. His best outing was one of his most recent, when he pitched six shutout innings against the Mets on March 28.
"He was superb, to say the least," manager Davey Johnson said. "He had a low pitch count and he started to get some pitches up in the sixth inning. But he had the low pitch count and just an unbelievable outing. That's Zim, the guy you've come to know and love."
In his career, Zimmermann is 0-2 with 12 earned runs in 18 innings against the Cubs.
One of the tough hitters he'll face is Cubs shortstop Starlin Castro, who was 2-for-4 on Saturday and has now reached base safely in 42 consecutive games dating back to Aug. 15 of last year.
It's the longest current streak in the Majors, and only three Cubs players in the last 94 years have reached base in as many consecutive regular-season games: Riggs Stephenson (44 games in 1928), Jerome Walton (43 in 1989) and Gabby Hartnett (42 in 1937).
Nationals: Tracy coming through in the clutch
Chad Tracy, getting his first big-league at-bats since 2010, is making the most of his opportunities in a Nationals uniform already this season.
The 31-year-old utility man came through with a pinch-hit two-run single in the eighth inning Saturday to help fuel the Nationals' five-run rally for their second win of the season. He also doubled in one of his two at-bats on Opening Day.
Cubs: LaHair expected to debut
First baseman Bryan LaHair, who has been battling back tightness for the last week, is expected to make his first start of the season in Sunday's series finale.
The 29-year-old, entering his first full season with the Cubs, received treatment on the Cubs' off-day Friday and has been hitting off a batting tee. He appeared as a pinch-hitter in Saturday's game and popped out.
"If everything goes good like it did [Friday] -- he's feeling great today -- he'll be in the lineup [Sunday]," manager Dale Sveum said Saturday.
The back end of the Cubs' bullpen has struggled already this season, as Carlos Marmol and Kerry Wood have combined to allow six runs in just 2 2/3 combined innings. They combined to allow five hits, five runs and two walks in 2/3 of an inning Saturday.
The Nationals won four of the seven meetings between the two teams last season, but just one of three at Wrigley. The two clubs won't meet again this year until Sept. 3-6, for a four-game series in Washington.