The Pirates probably have bad memories of the last time they faced the St. Louis Cardinals starter on his home field.
Wainwright (4-1, 1.46 ERA) went 2-0 with a 1.13 ERA and 15 strikeouts in two home starts against Pittsburgh in last year's NL division series, closing out the Pirates by scattering eight hits in a 6-1 victory in Game 5.
The right-hander has been similarly dominant so far this year, ranking among baseball's leaders in ERA, WHIP (0.81) and opponents' batting average (.165).
He yielded four hits over seven innings in Tuesday's 3-0 road victory over the New York Mets. The only thing that stopped Wainwright was a hyperextended right knee that caused him to leave after 79 pitches, but he has been cleared and says there is only pain when his leg is fully extended.
"When you look at the way I pitch, you barely do anything stiff-legged, so I'm going to be OK," he told the Cardinals' official website.
Wainwright's lone defeat this year came April 6 against the Pirates, as he yielded two runs in seven innings of a 2-1 road loss.
Edinson Volquez (1-1, 1.93) will oppose Wainwright again after allowing one run over 5 2-3 innings in that contest and not receiving a decision. Volquez suffered his first loss Tuesday, yielding two runs in seven innings of a 4-1 loss to Cincinnati as he was up against another outstanding starter in Johnny Cueto.
The Pirates right-hander is 1-3 with a 6.26 ERA in five career starts at Busch Stadium. He has dominated St. Louis star Yadier Molina, who is 3 for 23 against him.
Matt Holliday has enjoyed more success with eight hits in 22 at-bats versus Volquez, and he's 4 for 7 in this series.
Pittsburgh (10-15) will likely want to see a lengthy outing from Volquez since its bullpen was forced to work the final seven innings in Saturday's 6-1 victory after starter Francisco Liriano left with flu-like symptoms and dizziness.
Molina went 0 for 4 as his 15-game hitting streak ended on his jersey giveaway day. He fell to 3 for 19 against Pittsburgh this year.
St. Louis (13-12) has dropped five of seven, scoring a major league-low 10 runs over the previous seven days. The Cardinals haven't homered in 10 games.
Allen Craig continues to sputter with a .174 average. He's 1 for 18 against the Pirates.
Pittsburgh ended a season-high four-game slide Saturday. Gaby Sanchez had two RBIs in a four-run fourth inning.
"We got some key hits that we haven't been getting," Sanchez said. "We were finally able to put something together and get some runs across. It was good to get the lead and stay ahead."
Catcher Tony Sanchez had a two-run single in the ninth after being recalled earlier in the day from Triple-A Indianapolis to take the roster spot of Russell Martin, who was placed on the 15-day disabled list with a strained left hamstring.
Pittsburgh star Andrew McCutchen is a .419 hitter in the regular season against Wainwright, but went 1 for 7 against him in last year's playoffs.