(Sports Network) - The last time Randy Johnson took the mound the bullpen blew his solid performance. Tonight, the Big Unit will try again to lead the Arizona Diamondbacks to victory in the second test of a three-game series against the Milwaukee Brewers at Miller Park.

Johnson gave up just two runs and six hits in seven innings against the San Francisco Giants last Thursday before the bullpen imploded in a 4-3 setback. Johnson did not factor in the outcome and is 4-1 with a 3.83 earned run average in nine starts this season.

The 44-year-old lefty is 4-0 with a 3.95 ERA through his previous seven starts, with the Diamondbacks going 5-2 over that span. Johnson is 18-7 with five complete games and a 3.44 ERA in 30 career outings against Milwaukee.

Arizona leads the NL West by 3 1/2 games over the Los Angeles Dodgers despite having dropped six of its last eight games. It had a two-game winning streak come to an end after Monday's 4-3 loss to the Brewers in the series opener, as Chris Snyder homered and knocked in two runs, and Mark Reynolds had the other RBI and two singles in defeat.

D'Backs reliever Doug Slaten gave up Prince Fielder's eventual game-winning homer in the eighth inning to absorb the loss, while starter Doug Davis allowed three runs -- one earned -- in six innings of work. Arizona is 0-1 on a 10-game road trip against the Brewers, Pirates and Mets, and 11-14 away from the desert this season.

Fielder finished with three hits and scored twice for Milwaukee, which has won four straight to improve to 6-1 on a nine-game homestand. Bill Hall had an RBI and scored a run, and relief pitcher Guillermo Mota tossed a perfect eighth inning for the win. Salomon Torres pitched the ninth for his sixth save and starter Jeff Suppan was reached for three runs over seven frames.

Milwaukee is 17-10 at home this season and seven games off the pace in the NL Central standings.

Taking the hill for the Brewers tonight will be Seth McClung, who is 2-2 with a 4.80 ERA in 13 games (two starts) this season.

McClung last toed the rubber on May 29 versus Atlanta, allowing six runs and eight hits over 4 2/3 innings of an 8-1 defeat.

The right-hander has faced Arizona just once in his career on August 21 of last season. In a 7-4 victory at Chase Field, McClung was reached for a pair of runs and three hits in just two-thirds of an inning for the no-decision.

Arizona and Milwaukee are facing off for the first time since the Brewers won five of seven meetings in 2007, with a 3-1 record at Miller Park.