[2] Woodruff made his professional debut that year with the Helena Brewers and spent the whole season there, going 1–2 with a 3.28 ERA in 14 games (eight starts).

[13] He opened Game 1 of the NLDS against the Colorado Rockies, pitching three scoreless innings in the Brewers' eventual 3–2 win.

In Game 1 of the 2018 National League Championship Series against the Los Angeles Dodgers, Woodruff hit a home run off of Clayton Kershaw.

[19] He started the Wild Card Game, pitching four innings with his only blemish a home run hit by Trea Turner.

The Brewers lost to the eventual World Series champion Washington Nationals, with Hader taking the loss and a blown save.

[20] In the shortened 60-game season, Woodruff started in 13 games, tied for the most in the National League, going 3–5 with a 3.05 ERA and a 0.99 WHIP.

The Brewers again lost in the Wild Card round to the team that won the World Series, this year the Dodgers.

On January 13, 2023, Woodruff signed a one-year, $10.8 million contract with the Brewers, avoiding salary arbitration.

[22] Woodruff made two starts for Milwaukee, posting an excellent 0.79 ERA before he was placed on the injured list with shoulder tightness.

[26] On October 13, it was announced that Woodruff underwent right shoulder surgery to repair his anterior capsule, expecting him to miss most of the 2024 season.