Arizona @ St. Louis preview

Last Meeting ( Jul 8, 2011 ) Arizona 7, St. Louis 6

THE STORY: Chris Carpenter is starting to turn his nightmare season around. That is great news for the St. Louis Cardinals, who hope Carpenter can help them avoid losing a season-high fourth straight at home Saturday. Arizona, a surprise contender in the National League West, is seeking a third straight win over St. Louis. Kelly Johnson hit a go-ahead grand slam in the seventh inning of a 7-6 victory Friday.

TV: 7:15 pm. ET, Fox Sports Midwest, Fox Sports Arizona

PITCHING MATCHUP: Diamondbacks RH Daniel Hudson (9-5, 3.75) vs. Cardinals RH Chris Carpenter (4-7, 3.74 ERA). Carpenter, the 2005 NL Cy Young Award winner, dropped five straight decisions earlier in the year but appears to have solved his issues. He has won each of his last three starts, posting a 0.75 ERA in that span. The righthander yielded just six hits in eight innings of a 1-0 win over Cincinnati on Monday. He’ll try to avenge his worst outing of the season, which came on April 12 when he allowed eight runs in four innings of a 13-8 loss in Arizona. Carpenter is 4-1 with a 3.50 ERA in 12 appearances – 11 starts – vs. the Diamondbacks. Johnson is 7-for-18 with a homer against Carpenter, but All-Star Justin Upton (1-for-13) hasn’t fared as well against him. Despite a rare bad outing, Hudson still hasn’t lost in nearly two months. The righthander was roughed up for six runs – five earned – and eight hits in a season-low four innings, but was let off the hook when the Diamondbacks rallied for an 8-6 win over Milwaukee on Monday. He had been 6-0 with a 2.77 ERA in 10 starts since his last loss May 12. He has never faced St. Louis.

ABOUT THE CARDINALS (47-43): The Cardinals have two of the hottest hitters in baseball and neither is named Albert Pujols, who is still shaking off the rust from a shorter-than-expected stint on the disabled list. Lance Berkman hit his NL-leading 24th homer Friday, and Matt Holliday belted his fourth in as many games. Berkman has homered in five straight games against Arizona, while Holliday is hitting .389 (7-for-18) over the last four. Pujols, meanwhile, went 0-for-3 and has just one hit in 12 at-bats since returning a mere two weeks after suffering a broken left wrist.

ABOUT THE DIAMONDBACKS (49-41): Few expected the Diamondbacks, who lost 97 games last season, to be nipping at the defending World Series champion San Francisco Giants’ heels at the half-way mark. But they are, and one reason is because of their improved play on the road. Friday’s win was the 25th away from Chase Field, surpassing the Diamondbacks’ entire 2010 total. Arizona improved to 5-3 on a 10-game road trip. Johnson, whose 16 homers are the most by a second baseman prior to the All-Star break in franchise history, is also a big factor in Arizona’s impressive first-half. Chris Young, who had a two-run triple Friday, could find more success against Carpenter. He's 9-for-15 with a pair of homers off the Cardinals' ace.

FINAL PITCH: The Diamondbacks’ winning percentage of .418 (41-57) against St. Louis is their lowest against any NL team.