(My Sportsbook) - The race in the National League West division is starting to get interesting now that the Arizona Diamondbacks have hit a snag. The current division leaders will try to get back on track this afternoon in the opener of a three-game series versus the St. Louis Cardinals at Chase Field.

Arizona has dropped two straight and seven of its last nine contests to watch its lead in the NL West shrink to just 2 1/2 games over the Los Angeles Dodgers. Los Angeles just took two of three from the D'Backs in Phoenix to make up ground in the division standings.

In Sunday's 8-1 setback in the finale of the three-game series, Arizona starter Brandon Webb failed again in his bid for win No. 20 after giving up eight runs -- six earned -- and eight hits in only 3 1/3 innings of work. Mark Reynolds finished 2-for-3 with a home run for the Diamondbacks, who fell to 1-2 on their six-game homestand and 38-30 as the host.

The Diamondbacks will hand the ball to veteran left-hander Randy Johnson in Monday's series opener with the Cardinals, and he is 1-2 with a 2.88 earned run average over his last five starts. Johnson has recorded back-to-back no- decisions and did not factor in the outcome of a 5-4 loss at San Diego on Wednesday.

Johnson allowed three runs and five hits in seven innings, while striking out nine batters and giving up one walk. The southpaw, who is 10-9 with a 4.02 ERA in 25 starts this year, will make his 14th career appearance against St. Louis today and is 6-6 with four complete games versus the Cards.

St. Louis was just swept in three games by the Houston Astros to kick off a six-game road trip and suffered a 3-0 loss in Sunday's series finale at Minute Maid Park. Albert Pujols and Aaron Miles each had two hits for the Cardinals, who have lost five of seven.

Pujols currently leads the majors with a .364 batting average, with Atlanta's Chipper Jones right behind at .359.

Cardinals starter Todd Wellemeyer suffered the loss despite a solid start, giving up just one run and four hits over seven innings. St. Louis is 6 1/2 games off the pace in the National League Wild Card standings.

Joel Pineiro will handle pitching duties for the Cards on Monday, and will return to the starting rotation after a three-inning relief stint during an 18-3 win over Atlanta on August 22. He allowed two runs in three innings to collect the save and remain 6-5 on the season to go along with a 4.83 ERA.

Pineiro, a right-hander, is 3-0 with a 3.60 ERA in his last three starts. He defeated Cincinnati the last time he opened a game on August 16, allowing three runs and seven hits in six innings of work. He will make his first start versus the Diamondbacks and has no record in two relief appearances against them through five innings pitched.

St. Louis and Arizona are meeting for the first time since the Diamondbacks won four of seven meetings a year ago, including all three matchups in Phoenix. The D'Backs are 8-6 in their last 14 games against the Cardinals, with a 6-1 mark in the desert.