The Milwaukee Brewers selected Williams in the second round, with the 54th overall selection, of the 2013 MLB draft.[4] He signed with the Brewers for a $1.35 million signing bonus rather than enroll at the University of Missouri.[5]
On August 5, 2019, the Brewers selected Williams' contract and promoted him to the major leagues.[8] He made his debut on August 7 against the Pittsburgh Pirates at PNC Park.[9] In 13 appearances with the 2019 Brewers, Williams pitched to a 3.95 earned run average (ERA) while striking out 14 batters in 13+2⁄3innings pitched.
Williams was named the NL Reliever of the Month for September 2020. In 13 innings, he surrendered just four hits, no runs and recorded 24 strikeouts.[10] On October 5, 2020, Williams was named MLB Reliever of the Year, capturing 12 of 17 votes. Williams had a breakout year finishing with an ERA of 0.33, surrendering just 18 hits in 27 innings and 53 strikeouts. He struck out over half the batters he faced in 22 appearances. On November 9, 2020, Williams was named the NL Rookie of the Year, becoming the first relief pitcher to win the award since Craig Kimbrel in 2011.[11] His 0.33 ERA was the lowest in a single season with at least 21 innings pitched since earned runs became an official statistic in 1913.[12]
Williams returned to the Brewers' bullpen for the 2021 season. After allowing only a single earned run in 14 relief appearances during August, he was named NL Reliever of the Month for the second time.[13] On September 29, 2021, it was announced that Williams would miss the remainder of the season after fracturing his pitching hand after drinking alcohol and punching a wall following the celebrations following the team's NL Central Division title clinch the Sunday before.[14]
The Brewers traded Josh Hader, their closer, at the 2022 trade deadline, and Williams succeeded him as their closer.[15] In October 2022, it was announced that Williams intended to represent Team USA in the 2023 World Baseball Classic.[16][17]
On January 13, 2023, Williams agreed to a one-year, $3.35 million contract with the Brewers, avoiding salary arbitration.[18] He had a 1.53 ERA with 36 saves, and won the NL Reliever of the Year award for the second time.[19]
Williams signed a one-year contract for the 2024 season worth $7.25 million with a club option for the 2025 season worth $10.5 million.[20] On March 14, 2024, it was announced that Williams would miss roughly three months of action with two stress fractures in his back.[21] He was activated from the injured list on July 28.[22] In 22 appearances for Milwaukee, Williams logged a 1.25 ERA with 38 strikeouts and 14 saves over 21+2⁄3 innings pitched.
In the 2024 National League Wild Card Series against the New York Mets, Williams was brought in to close Game 3 with the Brewers leading 2–0. He allowed four runs in the top of the ninth inning, as Milwaukee eventually lost the game and their sixth straight playoff series.[23] At the end of the 2024 season, the Brewers declined the option on Williams' contract.[24]
Williams has two primary pitches: a four-seam fastball and a circle changeup with screwball-like movement while rotating the ball off the ring finger during release, which is also similar to a cricketleg-spinner bowling a googly,[citation needed] but at a much faster pace of around 85 mph and with a very high spin-rate of 2,852 rpm. He also has a rarely-used cutter and sinker.[27] In 2020, due to the increased movement on the changeup, he increased its usage and often used it as a strikeout pitch.[28] He refers to his changeup as the "Airbender," a nickname coined by Rob Friedman.[29][30]
