Despite his recent woes, Wainwright still has a chance to become baseball's first 16-game winner Wednesday as the visiting St. Louis Cardinals wrap up a three-game series against the Pittsburgh Pirates, who could be without reigning NL MVP Andrew McCutchen.Wainwright (15-8, 2.52 ERA) has alternated wins and losses over his last eight starts and is 3-4 with a 4.70 ERA since the All-Star break. He's issued 3.48 walks per nine innings during those seven outings after posting a 1.76 mark in the first half.Wainwright allowed five runs and three walks over six innings in Friday's 5-4 loss at Philadelphia."I don't think there is going to be anyone surprised when I say it's just another -- I've been in a funk, there's no other way to say it," he told MLB's official website. "It's been a month and a half that's just been very frustrating baseball from my side of it. You can point to a million different things, but it comes down to I haven't been able to go out there and execute pitches like I'd like too. That's the goal going forward."Wainwright is 4-1 with a 0.80 ERA in his last six starts against the Pirates, including two in last year's Division Series. However, McCutchen has hit him hard, going 14 for 45 with seven extra-base hits, including the playoffs.It's unclear if Wainwright will have to face him following his early exit Tuesday. McCutchen, who left in the fifth inning because of discomfort in his left ribs, came off the disabled list with a similar injury last Tuesday."Today caught up to him in a couple of different ways," manager Clint Hurdle said of McCutchen, who crashed into the wall earlier in the game. "Tonight got to be a point where we didn't think we needed to push any farther than he did."The Pirates (68-64) went on to win 5-2 thanks to Ike Davis' tiebreaking, pinch-hit three-run homer in the eighth. Josh Harrison also homered for Pittsburgh, which climbed within 3 1/2 games of wild card-leading St. Louis (71-60) and is just behind San Francisco for the second spot.The Pirates now give the ball to Jeff Locke (5-3, 3.69), who is unbeaten in four starts this month.The left-hander is looking to win a fourth consecutive decision after throwing six innings of two-run ball in Friday's 8-3 victory at Milwaukee. However, he failed to record a strikeout for the first time this year and issued a season-worst six walks, giving him 12 in his last 16 2/3 innings.Locke went 1-1 with a 3.38 ERA in three starts versus the Cardinals last year. Matt Holliday is 4 for 8 against him and Wainwright is 2 for 4 with a double.The Cardinals have dropped 14 of their last 20 regular-season games at PNC Park. Leadoff man Matt Carpenter, hitless in his last 13 at-bats, is a career .173 hitter in Pittsburgh. First baseman Matt Adams has also struggled there, going 6 for 42 with 16 strikeouts.Aside from McCutchen, the Pirates could also be missing newly converted first baseman Pedro Alvarez, who exited Tuesday's game with a foot injury. He has three homers in the last four contests.