Tampa Bay Devil Rays/Rays (2006–2008) The
Tampa Bay Devil Rays selected Hammel in the 10th round of the
2002 MLB draft. He made his major league debut on April 11, 2006, against the
Baltimore Orioles and got his first victory as a starter on September 2, 2007, against the
New York Yankees. On July 17, 2006, while with the
Durham Bulls, he threw 8 1/3 innings of a combined no hitter on July 17, 2006 with
Juan Salas getting the final two outs, beating the
Columbus Clippers 4-1.
Colorado Rockies (2009–2011) On April 5, 2009, the Rays traded Hammel to the
Colorado Rockies for pitching prospect
Aneury Rodríguez. On October 11, 2009, Hammel started game three of the
2009 National League Division Series against the
Philadelphia Phillies. Though he looked strong initially, he ended up allowing four earned runs and the Rockies went on to lose the game. Hammel agreed to a two-year contract with the Rockies before the 2011
season.
Baltimore Orioles (2012–2013) The Rockies traded Hammel to the
Baltimore Orioles, along with pitcher
Matt Lindstrom, for pitcher
Jeremy Guthrie on February 6, 2012. In his Orioles debut, he took a no-hit bid into the 8th inning, with the Orioles eventually winning, 3–1, over the
Minnesota Twins. On June 16, 2012, Hammel led the Orioles to a 5–0 victory over the
Atlanta Braves, holding the Braves to one hit over nine innings. It was the first complete game shutout of his career and the first complete game by an Orioles pitcher in the
2012 season. On July 15, 2012, Hammel was placed on the 15-day disabled list to have a right knee surgery. Hammel started for the Orioles on
Opening Day in 2013. On June 1, 2013, during a game against the
Tigers, Hammel was ejected for the first time in his career, by home plate umpire
Hunter Wendelstedt. Hammel had given up three consecutive home runs and his next pitch hit
Matt Tuiasosopo in the shoulder with a slider.
Chicago Cubs (2014) On January 31, 2014, Hammel signed a one-year, $6 million contract with the
Chicago Cubs. Before being traded, he compiled an 8–5 win–loss record to go with a 2.98 ERA and 104 SO.
Oakland Athletics (2014) On July 4, 2014, the Cubs traded Hammel, along with pitcher
Jeff Samardzija, to the
Oakland Athletics in exchange for top
shortstop prospect
Addison Russell, pitcher
Dan Straily, outfielder
Billy McKinney, and a player to be named later. After the trade with the A's, he recorded a 4.26 ERA and a 2–6 win–loss record.
Return to Cubs (2015–2016) On December 8, 2014, after becoming a free agent following the end of the 2014 season, Hammel agreed to terms on a two-year, $20 million deal to return to the Chicago Cubs. Hammel finished the 2015 season with a 10–7 record and a 3.74 ERA. He had the highest
line drive percentage allowed (24.5%) of all major league pitchers. In game four of the
2015 National League Division Series vs. the
St. Louis Cardinals, Hammel was the starting pitcher and pitched only 3 innings allowing three hits, two runs, one home run, and walked three batters with a no decision in the Cubs' 6–4 win over the Cardinals. Hammel also was the starting pitcher in game four of the
2015 National League Championship Series vs. the
New York Mets. He only pitched innings, allowing four hits, five runs, two home runs, and walked two batters with the loss in the Cubs' 8–3 loss against the Mets. Hammel finished the first half of the 2016 MLB season with a solid 7–5 record and a 3.46 ERA. Hammel finished the season with a 15–10 record and a 3.83 ERA. Although he was not included on the Cubs' postseason roster, Hammel received his first World Series ring. On November 5, 2016, the Cubs declined Hammel's option for 2017 and he became a free agent.
Kansas City Royals (2017–2018) On February 8, 2017, Hammel signed a two-year, $16 million contract with the
Kansas City Royals. The contract includes a mutual option for the 2019 season. In his first season in Kansas City, Hammel struggled throughout the season, posting a record of 8-13 with a career worst 5.29 ERA in innings. Hammel began the 2018 season in the rotation but posted an ERA of 6.15 in 18 starts and was demoted to the bullpen. Overall, in 39 appearances with 18 starts, Hammel finished the season with a 6.02 ERA and a record of 4-14 in 127 innings. On October 30, 2018, the Royals declined his 2019 option, making him a free agent.
Texas Rangers (2019) On February 1, 2019, Hammel signed a minor-league contract with the
Texas Rangers. On March 22, 2019, the
Texas Rangers announced that Hammel had made the opening day roster.
Retirement On March 23, 2019, Hammel announced his retirement from baseball. ==Pitching style==