Michael Wacha is just looking for some run support.
Liriano (0-3, 4.54 ERA) has gone without a victory in 10 regular-season starts since earning a 5-4 win at Texas on Sept. 10.
Prior to this season, he had won his first four starts against St. Louis with a 1.16 ERA, including three victories in 2013. But the left-hander gave up four runs in six innings of a 6-1 loss to the Cardinals on April 5, then lasted just two innings in a 6-1 victory April 26 as he dealt with flu-like symptoms.
He again failed to pitch deep into his last outing, allowing five runs and six hits with three walks over 3 2-3 innings of an 8-6 win over Toronto on Saturday.
In his lone regular-season start against the Pirates in 2013, Wacha (2-3, 2.55) limited them to two hits over seven scoreless innings in a 9-2 victory Sept. 8. He then yielded one run and one hit in 7 1-3 innings in a 2-1 win in Game 4 of the division series Oct. 7.
The right-hander is 0-3 in his last four starts despite a 3.09 ERA, largely due to a 1.93 run-support average. He gave up a two-run homer in the sixth inning of a 3-0 road loss to the Cubs on Saturday.
"It's just frustrating, really," Wacha said. "I was pitching well and if I was able to get out of a jam there. ... But I served one up there and they go up two runs. You just can't afford that in that situation."
The Cardinals (18-17) have started to show more life offensively, winning three of four since that defeat while totaling 17 runs and going 12 for 33 (.364) with runners in scoring position. Matt Holliday drove in three runs in Wednesday's 7-1 victory at Atlanta, and Matt Carpenter went 3 for 4 to improve to 8 for 15 over his last four games.
"I wish we didn't have an off day tomorrow because of how well we swung the bats today," Peter Bourjos, who hit his first home run as a Cardinal, told the team's official website. "It would be nice to keep this rolling."
Liriano has also endured a dearth of support during his winless streak, getting an average of 2.38 runs. He's received two or fewer runs of support in six of seven outings this year.
However, the Pirates (14-20) also appear to have found a spark recently, averaging 5.3 runs and batting .306 while winning four of six. Andrew McCutchen is hitting .423 during that span while Pedro Alvarez has seven RBIs.
Pittsburgh had totaled 16 runs while hitting .190 during a 1-7 stretch April 22-May 1.
"We're starting to click on all cylinders now," said catcher Chris Stewart, who was 2 for 3 in Wednesday's 4-3 victory over San Francisco. "The pitching is starting to come around, and we're starting to get those hits in those big situations that we weren't before."
The Pirates have taken nine of the last 12 regular-season meetings in Pittsburgh.