The Pirates, who dropped their first series against the Cubs, expect to have Andrew McCutchen back in the lineup as they try to spoil Matt Garza's season debut in Tuesday night's opener of a three-game home set.
Pittsburgh (26-18) has won eight of 10 for its best start since beginning 29-15 in 1991. The Pirates are six games better than they were at this point last season in a year in which they led the NL Central at the All-Star break before fading.
One reason Pittsburgh faltered was its 5-8 record after the break against a Chicago team that lost 101 games. The Pirates have now dropped seven of nine at home against the Cubs (18-25) after losing two of three to start 2013 in a series that saw the clubs combine for 12 runs.
Pittsburgh had Monday off after McCutchen was a late scratch from Sunday's 1-0 home victory over Houston due to soreness in his right knee. He expects to play Tuesday.
"After our doctors saw him, he felt better about his situation," manager Clint Hurdle told the Pirates' official website.
McCutchen is 7 for 14 with five runs scored over his last three games, and he's 2 for 6 with a homer against Garza.
Garza (5-7, 3.91 ERA in 2012) will be activated off the disabled list for his first start since July 21. He missed the rest of 2012 with a stress reaction in his right elbow before missing nearly the first two months of 2013 with a strained left lat.
"It was a grind, mentally," he said. "Physically, I could do anything, but the mental part was the tough part. It was one setback after another, and it was, 'Keep going, keep going, keep going.' I'm just happy I'm here at the end of it and can't wait till Tuesday."
The right-hander threw 75 pitches in six scoreless innings in his final rehab outing for Triple-A Iowa on Thursday. Manager Dale Sveum plans to allow Garza to throw between 85 to 90 pitches against the Pirates.
"His durability is fine, he works so hard that that kind of stuff, that's probably the last thing we have to worry about with him," Sveum said.
Garza may have to be at his best to match up with Wandy Rodriguez (4-2, 3.25), who improved to 3-1 with a 1.35 ERA in four home starts after allowing one run over seven innings Wednesday in a 3-1 win over Milwaukee.
Rodriguez earned Pittsburgh's lone victory over Chicago this year with 6 2-3 innings of two-hit ball in a 3-0 win April 3.
Chicago has won five of its last seven on the road, as it starts a challenging week that includes a weekend trip to Cincinnati.
"It's two of the top teams in our division that are playing really well and pitching really well, so it's going to be tough scoring runs," Sveum said.