The teams will meet for the first of those games on Monday afternoon at Miller Park, where the Brewers will try to close a five-game gap on the National League Central leaders while also trying to hold off the St. Louis Cardinals in a tight NL wild-card race.
Both sides come into this critical three-game series on high notes: The Brewers have won four straight series since splitting two games at Wrigley Field last month and the Cubs have won 12 of their last 17.
Zach Davies gets the ball for Milwaukee in the series opener. It will be Davies' first start since May 29, when a shoulder injury landed him on this disabled list for the second time this season.
His rehab process was stunted along the way by back issues, but after throwing a complete-game shutout last week for Class A Wisconsin, the Brewers brought the right-hander back to face a team he has held to three runs in 11 2/3 innings this season.
Davies was looking to build on a strong finish to the 2017 season but has been limited to eight starts in 2018, going 2-5 with a 4.23 ERA.
"I'm actually glad we're putting him in that spot," Brewers manager Craig Counsell told reporters Sunday. "It's added motivation for him. He's very familiar with this setting and this team. There are no surprises here."
Davies has a track record of success against the Cubs, posting a 3.64 ERA in 12 career starts.
"I think with a good series here, it could change the make-up of this division a little bit," Davies said. "I don't think any game is bigger than just the next day's game, but it definitely could change some things."
Monday will mark the Brewers' first look at Cole Hamels since he joined the Cubs in a deal with Texas ahead of the non-waiver trade deadline.
The change of scenery salvaged the veteran left-hander's season. He was 5-9 with a 4.72 in 20 starts for Texas this year, but since the trade he is 4-0 with a 0.96 ERA, allowing just three earned runs in 39 innings spanning four starts.
"I love the fact that he was able to complete that game," Cubs manager Joe Maddon said. "That absolutely benefits him down the road."
Maddon is known to have a quick hook, so when the Cincinnati Reds loaded the bases in the ninth inning in an Aug. 23 game, the fact that he left Hamels in the game is a good indication of how well he still was pitching. There was no drop in velocity, which is usually a precursor to getting pulled.
Maddon's faith in Hamels was rewarded when Tucker Barnhart bounced into a game-ending double play.
The win improved Hamels' record to 4-0 with a 0.79 ERA for the Cubs after compiling a 4.72 ERA with the Rangers before the July 27 trade.
"To be a major league pitcher, you're going to have some tough times," Hamels told ESPN.com earlier this month. "You can't give in. You have to fight. That's what it's all about. They're not going to give in. Neither should you."
He'll be pitching on an extra day of rest after Maddon gave Alec Mills a spot start to allow his rotation to have an extra day of rest during a stretch of 20 games without days off.
That meant Hamels would miss a chance to face his former team, the Philadelphia Phillies, and current ace Aaron Nola.
"For me, ultimately, I just want to go out and pitch and win," Hamels said. "However, they're going to slot me is not my decision. For us right now, we have a lot of games with no days off, and all of us are pitching really well. So it's not fair to any individual to kind of move me around for this sort of situation."
Hamels has had his fair share of success against Milwaukee. In 14 career starts -- most of them while pitching for the Phillies -- Hamels is 7-3 with a 3.64 ERA.