With his rotation spot in question, Pittsburgh Pirates left-hander Jeff Locke will have to secure it during a month that's been notoriously bad for him in his career.

Locke looks for a better result in his second September start as the Pirates open a three-game road series against the last-place Cincinnati Reds on Monday.

The Pirates (81-54) trail St. Louis by 5 1/2 games in the NL Central despite taking two of three from the Cardinals over the weekend, but they're three ahead of the Chicago Cubs and 10 1/2 up on Washington in the wild-card standings.

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It remains to be seen what role Locke will play if Pittsburgh makes it to October.

Locke (7-9, 4.66 ERA) coughed up five runs in 3 2-3 innings of Wednesday's 9-4 loss to Milwaukee, and he is 2-3 with a 6.26 ERA since July 24. He has pitched six innings or more just once during that span, allowing 49 hits - seven of them home runs - in 41 2-3 innings while opponents have hit .292 against him.

Locke may find it difficult to regroup in September, a month in which he's gone 2-13 with a 6.60 ERA during his five-year career.

With A.J. Burnett on the verge of returning from an elbow injury, each start becomes more pressing for Locke, whose second-half ERA is 5.88.

"You don't take the mound saying, 'Gee, this could be the last one,'" Locke said. "You go out there and try to win the game for your team."

Pirates manager Clint Hurdle wasn't ready to talk about Locke's immediate future after his brief outing against the Brewers.

"I'm not going to get into that right after a guy goes 3 2-3 innings," Hurdle told MLB's official website. "Those are conversations we'll have internally. We continue to look at ways to make our team stronger all the time. Adjustments in any spot ... those are ongoing conversations."

The Reds (56-79) have lost 17 of 22 and sit last in the Central, but they're 9-4 against Pittsburgh this year and have given Locke trouble in three games. They have 21 hits and 11 runs - nine earned - in 16 innings against him, though that only amounted to one Cincinnati win.

Todd Frazier is 9 for 23 with two home runs against Locke, who is 3-2 with a 3.46 ERA against the Reds in 10 career starts.

Cincinnati's Anthony DeSclafani (7-10, 3.87) has trudged through his own struggles, failing to reach the sixth in two of his last three starts with a 5.09 ERA. The right-hander has lost three of his last four, and the Reds have dropped each of his last five.

He cruised into the sixth with a 3-1 lead Tuesday against the Cubs, but he only recorded two outs and was charged with two runs in the inning. DeSclafani allowed four hits and three runs overall and didn't factor into the decision of a 5-4 loss.

"I ran into some trouble," he said. "I just have to make better pitches."

Brandon Phillips has three games with three or more hits in his last four for the Reds, including a 3-for-4 day with a two-run homer in Sunday's 6-3 win over Milwaukee.

Burnett hasn't pitched since July 30 but could return as soon as Wednesday, while Pittsburgh first baseman Travis Ishikawa (lower back strain) is expected to come off the disabled list Monday.