Who Will Be the Cubs' Game 1 Starter in Milwaukee?

It's happening. The Cubs are advancing in the postseason for the first time since 2017. The pitching staff took care of business against a Padres team with some elite hitting talent (though their actual production never lived up to the hype).

Craig Counsell’s unique usage of his pitching staff won them the series -- they only allowed five runs over the three games -- though it's put the rotation in something of a bind ahead of the NLDS. As the team heads to Milwaukee on Saturday to square off with ace Freddy Peralta, the first question that needs to be answered is who will toe the rubber to start Game 1? We know Cade Horton likely won’t be available for at least the beginning of the series, if at all, and Shota Imanaga and Jameson Taillon are still resting after their Wild Card Round starts.

That leaves three options, assuming Counsell doesn't try to get cute with more openers against his former team.

Option 1: Colin Rea

Rea pitched 1 2/3 relief innings on Wednesday for his only action of the Padres series. The 35-year-old is coming off the best statistical season of his career, posting a 3.95 ERA across 32 games (27 starts). In September, Rea has been one of the most dependable starters on the roster, so it makes sense to continue to ride the hot hand. His 1.45 FIP in four starts ranked lowest amongst Cubs starters, and his 1.0 fangraphs WAR puts him in a tie for third amongst all starters in baseball over that time period. To put things in perspective, the only two starters ahead of him were Kevin Gausman and Logan Webb, and he was tied with the likes of the best pitcher in baseball, Paul Skenes, super prospect Bubba Chandler, as well as Cy Young contender Yoshinobu Yamamoto and Orioles’ ace Kyle Bradish. Rea has made two starts versus Milwaukee in 2025; one solid (3 ER over 5.2 IP) and one clunker (9 hits, 4 ER over 4 IP). It could be the hot September that earns Rea the Game 1 start, although it is worth noting that he has given up 14 home runs this season to lefties. The Brewers have Christian Yelich, Brice Turang, and Sal Frelick entrenched in their lineup regardless of the pitcher, but they can also add Jake Bauers and switch hitters Blake Perkins and Isaac Collins to their lineup as well, potentially making this a rough matchup for Rea.

Option 2: Matthew Boyd

Boyd threw 58 pitches on Tuesday to open the series. It was a questionable hook when Counsell pulled him early in the game, when he was throwing well. We’ve seen starters throw on three days rest in the postseason before, but those starters are usually ace level workhorses, not a mid-30s starter coming off the best season of his career. Although the 2025 All-Star may be Jed Hoyer’s best bargain bin pickup this season, since July 28, Boyd has an ERA over 5.00 across 11 starts. In six of those starts, he has given up at least four runs, something he had only done once prior in 2025. He has thrown the second-most innings of his career this season (179.2), and has not previously topped 100 innings this decade (185 IP in 2019). We’ve seen Boyd thrive all year, including in the Wild Card Round, but a lot of signs are pointing to him running out of gas. It would be smart to get him a few extra rest days instead of letting him go on short rest. Also, across 10 1/3 innings versus Milwaukee this season, Boyd has given up 10 runs. Yikes.

Option 3: Javier Assad

This is the Wild Card option, assuming Michael Soroka and Aaron Civale don't enter last-minute consideration. Assad has been one of the Cubs’ most reliable starters since he arrived in the majors in 2022. Although he dealt with injuries for most of this season, he still pitched to a respectable 3.65 ERA in eight games (seven starts) and registered the lowest WHIP of his career at 1.21. Assad did not face the Brewers in 2025, but in 2024, he did not allow a run in his two starts against them. Starting Assad would likely lead to another quick hook after 18 batters (twice through the lineup), regardless of how well he is pitching. We have seen Counsell lean heavily on the bullpen so far, so an Assad start would fit the current blueprint. It is worth noting that Assad did not give up a run in his last start of 2025, when he threw 5 1/3 shutout innings versus the Cardinals on Sunday. He can also be used in a multi-inning relief role, say, if Boyd starts Game 1 and can only give the team a few innings.

Who do you think will take the ball in Game 1 for the Cubs? Let us know in the comments!