The Cubs are just a game behind the Astros in the NL Central, thanks mostly to one of the best pitching staffs in baseball.
Chicago has gone 13-4 in September, and at 82-70 is already guaranteed of a winning season, just its seventh in 31 years.
“I hear a lot of guys that come through, whoever our starter is, they say they hate facing us,” said catcher Paul Bako, who came to Chicago after stints with pitching powerhouses Atlanta and Houston.
“It’s a big advantage.”
The Cubs will throw Zambrano against the Pirates in the first game and right-hander Juan Cruz in the nightcap.
Zambrano has been sensational since the All-Star break, going 7-2 with a 1.61 ERA over 11 starts. He is 13-10 with a 2.77 ERA on the season.
“These guys are stepping up and really pitching well,” Chicago manager Dusty Baker said of his starting pitchers.
Wood threw a four-hitter for his fourth complete game of the year Wednesday, striking out 11 as the Cubs swept the New York Mets with a 2-0 victory.
Chicago will face a surging Pittsburgh team that has won five of its last seven games.
The Pirates took three of four from the Reds and improved to 37-40 at home.
Pittsburgh has a chance for its first winning record at PNC Park, which opened in 2001. Four home games remain on the schedule, starting with Friday’s doubleheader.
STANDINGS: Cubs - 2nd place, 1 GB, NL Central. Pirates - 4th place, 12 GB, NL Central.
CUBS GAME ONE PROBABLE STARTER: Zambrano (13-10, 2.77 ERA). The 22-year-old right-hander went the distance his last time out, allowing one run and four hits in a 1-0 loss to Cincinnati on Sunday. Zambrano has held opponents to two runs or fewer in eight straight starts.
PIRATES GAME ONE PROBABLE STARTER: Josh Fogg (10-8, 4.71 ERA). Fogg is 3-2 with a 3.27 ERA in six career starts against Chicago. The right-hander has won two straight starts and four of his last five decisions. Fogg pitched seven innings, allowing three runs and five hits to earn a 5-3 win over Philadelphia on Saturday.
CUBS GAME TWO PROBABLE STARTER: Cruz (2-5, 5.56 ERA). Cruz did not earn a decision in his last start. The hard throwing right-hander gave up six runs and 10 hits in five innings as Chicago beat Cincinnati 9-6 on Saturday. He is 1-2 with a 4.35 ERA over his last five starts.
PIRATES GAME TWO PROBABLE STARTER: Salomon Torres (5-5, 4.94 ERA). Torres hasn’t won since beating Cleveland 5-4 on June 20. The 31-year-old righty is 0-2 with a 9.00 ERA in three September starts. Torres went only 1 2-3 innings after giving up seven runs and six hits in a 10-7 loss to Philadelphia on Sunday.
OFFENSIVE LEADERS: Cubs - Mark Grudzielanek, .318 avg.; Sammy Sosa, 35 HRs; Aramis Ramirez, 96 RBIs; Kenny Lofton, 91 runs and 29 SBs. Pirates - Jason Kendall, .325 and 80 runs; Reggie Sanders, 31 HRs, 87 RBIs and 15 SBs.
SEASON SERIES: Cubs, 6-5.
STREAKS AND NOTES: Cubs - OF Moises Alou is hitting .367 in September. … The Cubs have four pitchers with at least 13 wins for the first time since 1945. … OF Sosa is 4-for-12 lifetime against Fogg with three home runs. Pirates - If Friday’s doubleheader against the Cubs is rained out, the teams probably would play back-to-back doubleheaders Saturday and Sunday. … Pittsburgh has pitched 10 shutouts this season. … The Pirates were 8-21 in their first 29 homes games but are since 29-19 at PNC Park.
ROAD/HOME RECORDS: Cubs - 40-34 on the road; Pirates - 37-40 at home.
INJURIES: Cubs - OF Corey Patterson (knee), 60-day DL; RHP Scott Chiasson (elbow), 60-day DL; LHP Will Ohman (elbow), 60-day DL. Pirates - IF Pat Meares (hand), 60-day DL; IF Pokey Reese (thumb), 60-day DL; RHP Kris Benson (shoulder), 60-day DL; LHP Dave Williams (shoulder), 60-day DL.