San Francisco Giants in 2005
spring training. Williams was the
San Francisco Giants first-round draft pick in the
1999 Major League Baseball draft, the 39th overall selection. He spent years in the
minors, compiling a record of 27–26 before being called up in 2003. He was a regular starter in the Giants rotation in 2003–2004, going 7–5 with a 3.30
ERA in 2003. In 2004, Williams started 22 games for the Giants, recording 10 wins with a 4.24 ERA. In 2005, Williams started 3 games for the Giants before being traded to the Cubs.
Chicago Cubs He was acquired by the
Chicago Cubs along with
David Aardsma for
LaTroy Hawkins during the 2005 season. In Williams' Cubs debut, he pitched 7 innings, giving up 2
runs and
striking out six
Milwaukee Brewers players, and ended up going 6–8 for the Cubs. Williams, however, played most of 2006 with the Cubs' Triple-A affiliate, the
Iowa Cubs, appearing only in 5 games for the Cubs.
Washington Nationals On January 12, 2007, Williams was signed by the
Washington Nationals organization and in
spring training earned a slot in the Nationals starting rotation. Williams had a rough April for the Nationals, his ERA ballooning to 7.77 before he pitched a brilliant game at the end of the month, pitching six innings of one-hit shut-out ball against the
New York Mets. But he sprained his left ankle sliding into
second base, and landed on the 15-day
disabled list. He came back on May 15, lasting only two innings, allowing five runs on seven
hits, and leaving with a rotator-cuff injury. His rehabilitation in the minors did not go well, and after 14 appearances with Double-A
Harrisburg, in which he compiled a 9.08 ERA, on August 5, he was released.
Minnesota Twins On August 8, 2007, he signed a minor league contract with the
Minnesota Twins. Williams, however, struggled mightily with Rochester and in 8 games had an ERA of 9.00 and was let go after the season.
Long Beach Armada In April , he signed a contract with the
Long Beach Armada of the
Golden Baseball League.
Los Angeles Dodgers On June 24, 2008, the
Los Angeles Dodgers purchased his contract and he played in their minor league system through the end of the season.
Oakland Athletics At the end of the minor league season, September 5, 2008, Williams was waived by the Dodgers and then claimed by the
Oakland Athletics. Williams did not play for Oakland and was not tendered a contract after the season, making him a
free agent. He subsequently re-signed with Oakland and spent 2009 with their top farm club, the
Sacramento River Cats of the
Pacific Coast League.
Indios de Mayaguez and Uni–President Lions Williams played winter baseball for the
Indios de Mayaguez in
Puerto Rico in 2008–09. He played for the
Uni-President Lions of CPBL in
Taiwan during 2010.
Los Angeles Angels of Anaheim On June 16, 2011, Williams signed a minor league contract with the
Los Angeles Angels of Anaheim. He was assigned to the Triple-A
Salt Lake Bees. Williams had his contract purchased on August 16, after recording a 3.91 ERA in 11 games and innings in Triple-A. On August 21, 2011, Williams acquired his first major league win since 2005 in his first major league start since 2007. He finished the season with a 4–0 record in 10 games. In June 2012, Williams had breathing problems and later collapsed in the clubhouse, forcing the Angels to place him on the
disabled list. For the first time since his rookie year, Williams spent the whole season in the big leagues. He was a key asset for Anaheim out of the bullpen, being their long man/spot starter. Williams appeared in 32 games, and made 15 starts for the Angels. He compiled a 6–8 record with a 4.58 ERA. In 2013, Williams made 25 starts for the Angels, appearing in 37 games overall. After recording a 9–10 record with a 4.57 ERA in 2013, Williams was non-tendered by the Angels, making him a free agent.
Houston Astros On February 6, 2014, Williams signed a one-year contract with the
Houston Astros. He was designated for assignment on July 1, 2014. He was released on July 8.
Texas Rangers On July 11, 2014, Williams inked a minor league deal with the
Texas Rangers. He was designated for assignment on August 8.
Philadelphia Phillies On August 10, 2014, the
Philadelphia Phillies claimed Williams off waivers. On September 20, Williams became the first pitcher in MLB history to defeat the same club with three different teams in the same season, defeating the Athletics with the Astros, Rangers, and Phillies. He signed a one-year contract to stay with the Phillies on October 21, 2014.
St. Louis Cardinals On June 3, 2016, the
St. Louis Cardinals signed Williams to Minor League contract. He was immediately added to the rotation of the
Memphis Redbirds, their
AAA team.
Somerset Patriots On May 12, 2017, Williams signed with the
Somerset Patriots of the
Atlantic League of Professional Baseball. He became a free agent following the season. In 11 starts 47.2 innings he went 2-4 with a 4.91 ERA with 32 strikeouts and throwing 1 complete game.
Acereros de Monclova On May 4, 2018, Williams signed with the
Acereros de Monclova of the
Mexican Baseball League. He was released on July 3. In 4 starts 22.2 innings he struggled going 2-2 with a 5.96 ERA with 8 strikeouts.
Retirement Williams' retirement from baseball was confirmed on December 10, 2018. ==Coaching career==