The Reds have already clinched the division title, so they'll be focused on lineups and pitching-rotation decisions while waiting to find out who their first-round opponent might be.
The Brewers will be clawing for an elusive NL Wild Card spot and need to win just about every night. Their blowout loss to the Nationals on Monday afternoon pushed them 3 1/2 games behind the Cardinals for the final berth.
Tuesday's game represents a huge challenge for Brewers starter Mike Fiers, who will be opposed by Reds right-hander Johnny Cueto.
Fiers lasted only three innings in his last start, which raised questions about his workload. Fiers, 27, has thrown 172 1/3 innings this season between Triple-A Nashville and Milwaukee, a professional high, and there have been whispers that he might have hit a wall.
In the last outing, against Pittsburgh, he threw 81 pitches in his three innings before being pulled by manager Ron Roenicke. It continued a pattern of Fiers' performance slowing down as the season has worn on. The right-hander had a 1.81 ERA and .218 opponents' batting average in his first 13 appearances this year, including 12 starts, but since then, in eight starts, he has a 6.75 ERA and a .298 opponents' average.
Fiers said he does not agree that he's wearing down, though.
"I don't think that's the deal for me. I still feel strong," Fiers said. "I'm just not hitting my spots. I'm not getting it done. I have pitched the most innings I have ever pitched, but I'm not going to use that as an excuse. It's just bad pitching on my part."
He'll try to rebound from that, while Cueto will continue his drive for 20 wins. He currently owns a 2.84 ERA to go with his 18-9 record, and has two starts remaining.
The Reds announced on Monday that Cueto was being moved up in the rotation, taking the spot of Mike Leake. Cueto, who will be pitching on normal rest, had an 8.22 ERA in his last three starts before Thursday, when he tossed six scoreless innings against the Cubs despite issuing four walks and striking out two.
"I don't think that was the best stuff he's ever had," Cubs manager Dale Sveum said. "You could tell he might be getting a little tired at the end of the year. I've seen him with better stuff."
Brewers: Aoki is A-OK
Outfielder Norichika Aoki's 12-game hitting streak ended Sunday, but he still had other streaks of 15, 13 and 10 this season, making him the first NL rookie since the Cardinals' Bake McBride (1974) to produce four hitting streaks of at least 10 games in a season. McBride, the 1974 Rookie of the Year, had two 10-game streaks and two 12-game streaks.
With his next stolen base, outfielder Ryan Braun (40 home runs, 29 stolen bases) will have just the third 30/30 season in franchise history and the second of his career.
Reliever John Axford has not been scored upon in 13 of his last 15 appearances, posting a 1.98 ERA (13 2/3 innings pitched, three earned runs). He has converted 15 consecutive save opportunities, and joined Dan Plesac (133) as the only Brewers pitchers to reach 100 saves (104) and produce 30 or more saves in consecutive seasons (Plesac, 1988-89).
Reds: Strikeout kings
The 2012 Reds are only the 15th team in Major League history, and the first since the 2009 Braves, to produce at least six pitchers with at least 100 strikeouts each (Bronson Arroyo, 122; Homer Bailey, 152; Aroldis Chapman, 119; Johnny Cueto, 159; Mat Latos, 178; Leake 113). The 1964 Reds also did it (Sammy Ellis, 125; Joey Jay, 134; Jim Maloney, 214; Joe Nuxhall, 111; Jim O'Toole, 145; John Tsitouris, 146). No team in Major League history has produced a staff of at least six pitchers with 120 strikeouts each.
According to Elias Sports Bureau, outfielder Jay Bruce is the first player in Major League history to hit at least 20 homers as a rookie and then improve on that total in each of the next four seasons (21 in 2008, 22 in '09, 25 in '10, 32 in '11, 34 in '12).
In the last 18 games, Reds relievers have posted a 1.61 ERA (56 innings, 10 earned runs).
Brewers reliever Jim Henderson pitched a perfect eighth inning on Sunday and has not been scored upon in his last seven appearances (5 2/3 innings pitched).
Reds reliever Sean Marshall hasn't allowed an earned run in any of his last 12 appearances (9 1/3 innings pitched, one unearned run) and hasn't allowed a run in any of his last 10 appearances (7 2/3 innings pitched.)