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(SportsNetwork.com) - Hoping to avoid losing more ground in the race for first place in the National League Central, the St. Louis Cardinals turn to one of their two recent additions to the rotation.

Justin Masterson gets the nod on Saturday evening for the Cardinals in the second contest of a three-game set with the first-place Milwaukee Brewers.

Masterson was acquired from the Cleveland Indians on Wednesday and the Cardinals made another big move the following day ahead of the non-waiver trade deadline, getting John Lackey from the Boston Red Sox in exchange for outfielder Allen Craig and starter Joe Kelly.

Lackey will make his debut in Sunday's finale and hopes to be following a victory by Masterson, who was 14-10 with a 3.45 earned run average for the Indians a season ago but has gone just 4-6 with a 5.51 ERA in 19 starts this year.

Masterson will be pitching in the majors for the first time since July 7 as he had been sidelined with knee discomfort. The 29-year-old righty is 0-2 over his last five outings and will face Milwaukee for the first time looking for his first victory since June 8.

"It's great to be able to come here," Masterson told St. Louis' website. "A winning tradition [where you] have a chance. That's right where you want to be."

The Cardinals dropped Friday's opener 7-4 as ace Adam Wainwright was blitzed for seven runs over 5 1/3 innings. Manager Mike Matheny was ejected when he came to lift Wainwright, upset over a balk called on his starter in the fifth inning as well as a close play at second in the sixth in which Jean Segura was called safe and Matheny's challenge failed to overturn the call.

Though it appeared he made only a brief comment to second base umpire Will Little as he walked off the mound, Matheny said he gave Little "every reason" to eject him.

"What I saw was wrong," Matheny said following his club's seventh loss in 10 games.

Aramis Ramirez homered and drove in two runs for the Brewers, while Jonathan Lucroy notched a three-run double.

Wily Peralta went 6 2/3 innings for Milwaukee, allowing two runs on five hits and four walks to earn his fourth straight win. It was also Milwaukee's second in a row and it moved it three games up on the Cardinals for first place in the NL Central. The Pittsburgh Pirates are 2 1/2 games off the Brewers' pace.

"We'll just continue hopefully to play good baseball," Brewers manager Ron Roenicke said. "We need to concentrate on every game. They're all important."

Jimmy Nelson had been scheduled to start tonight for Milwaukee, but was scratched on Friday due to a blister. Kyle Lohse will move up to start in his place, with Matt Garza now in line to go Sunday and Nelson getting pushed back to Tuesday versus San Francisco.

Lohse, a former Cardinal, had a two-start winning streak snapped on Monday with a 2-1 loss to Tampa Bay. The righty allowed both runs on four hits and three walks in six innings, striking out six.

Lohse, 35, is 11-5 with a 3.07 ERA on the year and is 3-5 in his career against his former team with a 4.04 ERA in 10 starts.

St. Louis has split 10 meetings with Milwaukee this year after going 14-5 in this rivalry a season ago.