The Pirates know that if there was ever a time for them to get back on track, it's during their three-game series against St. Louis, and they didn't exactly get off to a good start in Monday's 4-3 loss.

On Tuesday, the Bucs will be trying to even the series, but more importantly, a victory would move them back to within two games of St. Louis for the second Wild Card spot in the National League.

James McDonald gets the ball for Pittsburgh, looking to rebound from a rough outing in his last start. McDonald (11-6, 3.73 ERA) walked the bases loaded in the first inning against the Padres before allowing three runs in that frame. He lasted just five innings.

"When he throws strikes, it's hard to hit," Pirates manager Clint Hurdle said. "It's flat out hard to hit. The batting average against, even when he's not good, doesn't really spike. More often than not, he's involved in the undoing."

Jake Westbrook takes the ball for the Cardinals, coming off a similar disappointing five-inning outing. He gave up five runs to Houston, though he was bailed out by his offense in a 13-5 victory.

"The sinker wasn't quite there," Westbrook said. "I was too elevated, mostly middle of the plate. I threw some bad cutters, which really hurt me, and I was kind of in trouble all day. Allowing three sac flies as a ground-ball pitcher, I guess that's an indication that I'm not very sharp."

Westbrook (13-9, 3.67 ERA) also hasn't been very sharp against Pittsburgh. In 12 games against the Bucs (eight starts), Westbrook is 1-6 with a 4.63 ERA, though he did allow just two runs (one earned) in 7 2/3 innings when the two clubs squared off earlier this month.

Cardinals: Freese expected to return
Third baseman David Freese appears set to return to the Cardinals' starting lineup on Tuesday as his bruised left wrist felt fine following a session in the batting cages Monday afternoon.

Freese missed three starts because of the injury, which he sustained on Friday when he was hit by a pitch. X-rays confirmed there was no fracture, and Freese was able to pinch-hit on Monday, striking out in the top of the eighth.

"I'm good," Freese said before Monday's game. "Actually, I thought I'd be in there today."

Pirates: Walker dealing with back tightness
Hurdle scratched second baseman Neil Walker from the Bucs' lineup with tightness in his lower back 90 minutes before the first pitch of Monday night's game.

Walker was set for further medical evaluation, and his status for Tuesday's game remains uncertain. He had been struggling recently with just four hits in his past 10 games.

In Walker's absence, Josh Harrison started at second, and Clint Barmes replaced Harrison at shortstop.

Worth noting
• Monday's Cardinals victory gave them a 7-6 edge in the season series between the two clubs. One more win in this series -- the last one between them this year -- would give St. Louis its fourth straight season series win over Pittsburgh.

• Pedro Alvarez's 16 RBIs against the Cardinals are the most of any Major League player against St. Louis this year.

• The Cardinals have 62 wins at PNC Park, the most of any opposing team.

• Andrew McCutchen (7-for-18), Walker (6-for-17) and Jose Tabata (8-for-19) have all hit Westbrook well, combining for a .389 batting average against the Cards right-hander.