While Adam Wainwright and Jeff Locke represented their respective teams at this year's All-Star game, neither has come close to pitching at that level of late.

With both starters looking to get back on track, the St. Louis Cardinals try to overtake the NL Central-leading Pittsburgh Pirates on Saturday night at Busch Stadium.

Wainwright (15-9, 3.14 ERA) is on the verge of losing a season-high third consecutive start after uncharacteristically getting knocked around in back-to-back defeats to Cincinnati. After surrendering a career-worst nine earned runs in two innings in a 10-0 rout Aug. 28, Wainwright yielded six runs in as many innings in Monday's 7-2 road defeat.

"Obviously, I'm frustrated," he told MLB's official website. "This team deserves more out of me, and the last two games, I haven't given them what they deserve.

"The last time, it was a matter of me leaving too many ball in the middle of the plate. Today, they hit some good pitches. I feel very strong. ... It's a head-scratcher, to be honest with you."

The Pirates (81-59) are hoping to see Locke (9-4, 3.22) regain his form after briefly sending him down to Double-A Altoona to clear his head. The left-hander, 0-2 with a 7.02 ERA in his last seven outings, will make his first start since yielding five runs in 4 2-3 innings in a 7-6 loss to Milwaukee on Aug. 27.

"I'm young, 25, but there is fatigue, and everyone says it's normal," said Locke, whose 148 1-3 innings are second on the team. "And we're not the only team doing something like this. I'm gonna want to take it every time, gonna want to keep going, regardless of how it's going.

"You gotta bring more than what I've been bringing. ... Just get away from it for a while, step back and hit the reset button."

Another poor showing could help St. Louis (81-60) climb atop the division. The Cardinals, who had scored 17 runs during a 2-6 stretch, moved within one-half game of Pittsburgh with Friday's 12-8 victory.

Jon Jay, Matt Holliday and Carlos Beltran combined for eight hits and seven RBIs, and Yadier Molina delivered a big a three-run homer.

"They made some mistakes over the plate and we did a real good job of taking advantage," Matt Carpenter said after posting his major league-leading 55th multihit effort.

Pittsburgh failed to get much going until scoring seven runs over the final two innings. Josh Harrison delivered a pinch-hit two-run homer and Jose Tabata had two RBIs.

"You've got to take one positive from tonight and that's this team and what they did to the final out," losing pitcher A.J. Burnett said.

The Pirates, hoping to avoid a third consecutive loss, are still one win from securing their first winning season since going 96-66 in 1992.

"It's a mile marker on the road," said manager Clint Hurdle, whose team has dropped five of eight to St. Louis.

Wainwright has been hit hard in his last five starts versus Pittsburgh, going 1-2 with a 6.00 ERA. Andrew McCutchen is 10 for 25 with five extra-base hits in their matchups, and Russell Martin is 9 for 21.

Locke threw seven innings of three-hit ball in a 9-0 win at St. Louis on April 28, but he was tagged for four runs and a career high-tying 10 hits in four innings against the Cardinals on July 31.

Locke will need to be careful against Holliday, who is 4 for 5 against him. The six-time All-Star has hit safely in 20 of 21 home games, going 30 for 72 (.417) with six homers and 24 RBIs.

Jay is 17 for 42 (.405) with eight RBIs and eight runs in his last 10 games versus Pittsburgh.