Pressure on Pirates in weekend showdown with Cardinals in St. Louis

Garrett Jones and the Pirates enter the weekend with a 1 1/2 game lead on Yadier Molina and the Cardinals. (AP) The Pirates and the Cardinals, the top two

Garrett Jones and the Pirates enter the weekend with a 1 1/2 game lead on Yadier Molina and the Cardinals. (AP)

The Pirates and the Cardinals, the top two teams in the National League Central, meet for the final time in the 2013 regular season this weekend with a three-game set in St. Louis. Pittsburgh enters the series with a 1 1/2 game lead over the Cards (two games in the loss column), but because of the relative strength of the two teams' remaining schedules after this weekend, the pressure remains on the upstart Bucs to take this series and increase their advantage in the division.

After this weekend, St, Louis has just three games remaining against a winning team: the Nationals, who are three games over .500. The Pirates, meanwhile, play three games against the Rangers in Texas starting Monday and play six of their final nine games against the Reds, who are also in the mix for the NL Central title. When weighted for the number of games scheduled, Pittsburgh's remaining opponents average a .492 winning percentage to the Cardinals' opponents' .451.

That is why a series win this weekend is especially crucial to the Pirates. Just using those winning percentages above, the difference between .492 and .451 over a 20-game span (after this series, Pittsburgh will have 20 games left, St. Louis 19) is more than a full win. If the Cardinals take two of three this weekend, they'll be just a half-game behind the Pirates (one game in the loss column), a difference that could be erased based on strength of schedule alone. Even if the Cards lose two of three, they stand a solid chance of making up what would be a two-game deficit in the loss column against their relatively weak opponents. That puts the onus on Pittsburgh to bury St. Louis this weekend.

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The Pirates have a 10-6 advantage in the season series (though that wouldn't come into play in a tie for the division, which would instead be broken via a one-game playoff). The two teams have split their previous six games in St. Louis thus far this season, but of the Cards' three home wins against Pittsburgh, one came in April and the other two were one-run wins in extra innings last month.

The Cardinals come into this series cold, having just gone 2-5 on a road trip against their fellow NL Central playoff contenders, and having just lost first baseman Allen Craig to a sprained left foot that will keep him out of this series entirely. St. Louis does have rookie slugger Matt Adams to take over for Craig at first base. Adams hit two home runs in extra innings on Wednesday to give the Cardinals their only win in a four-game series against Cincinnati. But even with those two homers, Adams has hit just .183/.256/.341 in 90 plate appearances since the All-Star break, including going 0-for-3 with two strikeouts against the Reds on Thursday.

The loss of Craig, who was hitting .315/.373/.457 on the season and leading the team with 97 RBI, comes at a bad time not only because of this weekend's series, but because the Cardinals' offense as a whole has been in a slump. In its last eight games, St. Louis has scored more than two runs just twice, scored more than three runs in nine innings just once (that coming in Pirates rookie Kris Johnson's first major league start) and been shut out three times. Its offense has averaged just 2.1 runs scored per game over that stretch and the team is 2-6 in those eight games.

The Cardinals will look to break that slump Friday night against Bucs starter A.J. Burnett, who held them to one run over seven innings last Saturday and is 3-0 with a 2.59 ERA in five starts (four quality) against St. Louis this season. Burnett's mound opponent will be Joe Kelly, who is 6-0 with a 2.16 ERA in seven starts since returning to the rotation in early July, including two wins against Pittsburgh in which he allowed a total of one run in 12 innings. Friday night's game is especially important to the Pirates, whose next win will be their 82nd, clinching their first winning season since 1992.

Saturday's pitching matchup has a very different flavor, as St. Louis' Adam Wainwright, coming off two ugly losses to the Reds in which he gave up a total of 15 runs in eight innings, will take on Jeff Locke, who was 9-3 with a 2.15 ERA after his first 20 starts this season, but was sent to the minors at the end of August after posting an 8.09 ERA and 2.32 WHIP over his last six starts. Locke hasn't pitched since and will make Saturday's start on 10 days of rest. Sunday will pit Pittsburgh's Charlie Morton (7-3, 3.00 ERA) against 22-year-old Cardinals rookie Michael Wacha, who held Cincinnati scoreless for six innings on Monday and pitched two dominant innings of relief against the Pirates in mid-August, but who will be making just his sixth major league start and just his second since early June.