Jake Westbrook owns the lowest ERA in baseball, but a visit to Wrigley Field could put that in jeopardy.
The Cardinals (20-12) have the best rotation in baseball with a 2.22 ERA, and Westbrook (2-1, 1.07 ERA) is a big reason for that.
The right-hander, however, is 2-1 with a 6.14 ERA while allowing the Cubs to hit .305 over three starts at Wrigley. Overall, he's 5-2 with a 4.14 ERA in eight starts and won the most recent matchup on July 21, when he yielded three hits in seven innings of a 12-0 home victory.
Westbrook enters this matchup after yielding one run in 12 innings over his last two starts, earning a 6-5 win in the latest one at Milwaukee on Thursday. That marked the sinkerballer's 100th career victory.
"One of the luxuries I have is that my ball still moves," the 13-year veteran told the team's official website. "Lot of times, whether it goes where I want it to or not, it still runs down in the zone. It still can be good, and I can have some success."
The Cubs (13-20) may be at the bottom of the NL Central, but they've won four of six at home against the Cardinals. They beat them again Tuesday, when Nate Schierholtz's two-run homer in the fourth provided the difference in a 2-1 victory.
"Any time we come in here, it's tough," manager Mike Matheny said. "This team plays us tough any time we come into Wrigley."
Chicago is trying for a third straight win at home for the first time since July 28-30, a stretch that included two wins over St. Louis.
Alfonso Soriano, who had two hits and a run Tuesday, has hit the Cardinals hard of late with a .327 average in 14 meetings. Much of that damage has come in nine home games, during which he's batting .389 (14 for 36) with seven extra-base hits.
Soriano, though, is 3 for 30 versus Westbrook, who has held the current Cubs roster to .218 at the plate.
Carlos Villanueva (1-2, 2.85) is slated to get the ball in an effort to avoid losing three straight starts for the first time in his eight-year career.
He'll try to draw some inspiration from Travis Wood's impressive performance Tuesday after he yielded one run with eight strikeouts in 6 2-3 innings to outpitch Lance Lynn.
Villanueva has lost back-to-back-outings, surrendering eight runs with 12 strikeouts in 11 2-3 innings.
"In my last two starts, I'm one pitch away from two quality outings," Villanueva said. "You know, the good part is I'm close to where I want to be. I'm just not putting that guy away when I need to."
The right-hander is 2-0 with a 4.00 ERA in his last three starts against the Cardinals, but he hasn't faced them since June 25, 2011.
He's held Yadier Molina to 3 for 18, but the Cardinals catcher is hitting .452 over his last eight games. He had two hits Tuesday, but killed a potential rally in the eighth by being picked off between second and third.
Matt Holiday has homered on two of his three hits in 10 at-bats versus Villanueva, but he's 3 for 20 over the last six games at Wrigley.