Milwaukee's lineup has struggled in the absence of Ryan Braun, and their next assignment isn't likely to make things any easier.
Simon (4-1, 4.60 ERA) has dazzled in place of the injured Mat Latos, allowing two runs or less with no more than five hits in each of his five starts. He earned a third straight win in Tuesday's 3-2 home victory over the Chicago Cubs, surrendering two runs and five hits in six innings, though Reds manager Bryan Price didn't think Simon had his best stuff.
"He got a little erratic there and fought his way through," Price told the team's official website. "That, to me, is the sign of his development. He's gotten himself into some sticky spots early in the game and he's pitched through and kept himself in the ballgame."
He's never started against Milwaukee but is 2-1 with a 3.46 ERA in nine relief appearances.
With a .183 opponents' batting average, Simon has given the Reds a formidable 1-2 punch along with ace Johnny Cueto, who struck out 10 and allowed three hits over eight innings in Saturday's 6-2 victory.
"Good managing is having great pitchers," Price said.
In seven games without Braun, who was put on the 15-day disabled list Saturday because of a strained oblique, the Brewers (21-10) are batting .204.
Their only offense Saturday came on a pair of solo home runs as third baseman Aramis Ramirez interrupted a 0-for-28 slump, while first baseman Mark Reynolds homered for the second time in three games. Reynolds has a six-game hitting streak, which matches his longest since a 10-gamer from Aug. 20-30, 2011.
Milwaukee has managed seven runs in the first three games of the series.
"It's hard to say what to do with the lineup," manager Ron Roenicke told the team's official website. "The guys are playing enough and if somebody's hot they're going to be in there more. As a group, we'll get it going."
The Reds (14-16) had more quality at-bats as they struck out just twice for the first time in 129 games.
"With these guys (the Brewers), it's going to be a heavyweight fight," said Reds catcher Brayan Pena, who is batting .309 as he fills in for the injured Devin Mesoraco. "They have the best record in baseball, but we've never backed down."
The Brewers will try to salvage a split with Kyle Lohse, who has been about as good as Simon lately. Lohse (4-1, 2.70) had won four straight starts before not factoring into the decision in Tuesday's 5-4 win in St. Louis. The right-hander allowed three runs and six hits while striking out nine in six innings. He's allowed six earned runs in his last four starts with a 7-to-1 strikeout-to-walk ratio.
In his first season with Milwaukee, Lohse went 2-1 with a 1.88 ERA in four starts against the Reds, including a complete game in the last meeting on Sept. 13.
No one in the Cincinnati lineup has been particularly successful against Lohse, especially former teammate Ryan Ludwick, who is 4 for 28 against him.
After a mostly strong April, the Milwaukee bullpen has started to struggle, yielding 11 runs in 10 innings over the last four games.
The Cincinnati bullpen hasn't been needed much, throwing just three innings in three games, but it has a 2.14 ERA in the last 10 games after posting a 5.77 ERA though the first 18.