Trevor John Cahill (born March 1, 1988) is an American professional baseball pitcher who is a free agent. He has played in Major League Baseball (MLB) for the Oakland Athletics , Arizona Diamondbacks , Atlanta Braves , Chicago Cubs , San Diego Padres and Kansas City Royals . He was named an All-Star in 2010, and finished that year 18-8 with a 2.97 ERA.
The Oakland Athletics drafted Cahill in the second round (66th overall) of the 2006 MLB draft out of Vista High School . In his first full season in minor league baseball , with the Kane County Cougars , he went 11–4 with a 2.73 earned run average , 117 strikeouts and 105 1 ⁄ 3 innings pitched over 19 starts to earn a Class A All-Star nod from Baseball America .
Cahill began 2008 with the Stockton Ports of the California League . He went 5–4 with a 2.78 ERA and 103 strikeouts to earn a California League All star selection and a promotion to AA. He also represented America in Major League Baseball's Futures Game .
Entering the 2009 season, Cahill was ranked 11th among Baseball America's Top 100 Prospects,  and made the Athletics starting rotation out of Spring training along with his Olympic teammate Brett Anderson . On April 7, 2009, Cahill made his Major League debut against the Los Angeles Angels of Anaheim , going 5 innings , allowing 5 hits , 2 earned runs , striking out 1 and received a no decision . 
Cahill came into the 2010 season as a starter for the A's, quickly becoming one of the breakout pitchers of the year. He put up borderline Cy Young Award-worthy statistics, finishing the season with an 18–8 record and an ERA of 2.97, making it into the Top 5 of lowest ERA in the American League, behind Félix Hernández , Clay Buchholz , and David Price , all three considered among best pitchers in the American League. His WHIP was also in the Top 5, with 1.11 WHIP.
For the 2011 season, high expectations were set for Cahill. Cahill began the season as the A's #1 starter. Cahill did not replicate his 2010 performance, despite logging in 207 innings in 34 starts. Cahill finished 12-14 with a 4.16 ERA for Oakland.
On December 9, 2011, Cahill and Craig Breslow were traded to the Arizona Diamondbacks for Ryan Cook , Jarrod Parker , and Collin Cowgill .  In his first season in Arizona, Cahill bettered his 2011 performance by going 13-12 in 32 starts. He pitched more than 200 innings for the second straight year and struck out a career high 156 batters.
In 2013, through 17 starts, Cahill was 3-10 with a 4.66 ERA. After his 17th start, Cahill was put on the disabled list for the first time in his career.  Cahill missed more than a month due to a hip contusion. He came back in mid August. After his stint in the disabled list, Cahill finished the season on a 5-game winning streak, finishing the 2013 season with a 8-10 record in 25 starts. He led the league in wild pitches with 17.
Cahill struggled mightily at the beginning of the 2014 season. He first began the season 0-4 with a 9.17 ERA, then he was demoted to the bullpen the following week.  Cahill made 15 appearances out of the bullpen, recording his first save of his career and lowering his ERA to 5.17. Despite this, Cahill's control didn't seem to get better, he was designated for assignment on June 9.  After going unclaimed, the D'Backs sent him to Single A to fix his mechanical issues.  After a month in the minors, Cahill was recalled on July 14.  Cahill was quickly inserted back into the rotation. Cahill finished his rocky 2014 season with a career worst 3-12 record and a career high 5.61 ERA in 32 games (17 starts) for the D'Backs.
On April 2, 2015, he was traded to the Braves in exchange for minor league player Josh Elander.  He made his Braves debut on April 14, yielding four earned runs in 2 1 ⁄ 3 innings.  On June 11, 2015, he was designated for assignment .  He was released on June 20. 
Los Angeles Dodgers
On July 2, 2015, Cahill signed a minor league contract with the Los Angeles Dodgers .  He started seven games in the Dodgers system between three levels and was 1–3 with a 5.24 ERA before exercising his opt out and becoming a free agent on August 14. 
Cahill signed a minor league deal with the Chicago Cubs on August 18, 2015.  On October 10th, 2015, Cahill pitched in the National League Division Series against the St. Louis Cardinals and pitched a scoreless inning of relief. It was only the third time he was used in the 8th inning or beyond in 2015.
On December 14, 2015, Cahill re-signed with the Cubs on a 1-year, $4.25 million contract. 
Cahill was mostly in the bullpen in 2016, making 50 appearances, finishing the year 4-4 with a 2.74 ERA. The Cubs finished the season with a 103-58 record for an NL Central pennant, and would eventually win the 2016 World Series . Cahill did not make any postseason appearances, but still won a World Series ring for the first time in his career. 
San Diego Padres
On January 20, 2017, the San Diego Padres announced they signed Cahill to a one-year contract.  Cahill signed with the Padres with the assumption he'd compete for a rotation spot. He began the season in the rotation before succumbing to a shoulder injury which sidelined him for over a month. In 11 starts, Cahill sported a career high 10.6 K/9 while reducing his walk rate. Overall, Cahill recorded 4 wins for the Padres with an ERA of 3.69 in 61 innings.
Kansas City Royals
Cahill attended Vista High School and committed to Dartmouth College before eventually signing with the A's.  He got a 1950 out of 2400 on the SAT .  In the offseason, he lives in Oceanside, California, with his wife, Jessica.
Cahill's best pitch is his sinker, which features excellent downward movement and ranges from 88–92 mph. His sinker is his most frequent offering and is the main reason why he gets so many ground balls. Cahill also has a changeup in the 81–83 mph range, which like his fastball also features excellent downward movement. This is a pitch that he uses frequently against left-handers to get strikeouts. Starting in the 2010 season, Cahill began featuring a 12–6 curveball as well. His curve, which ranges in the 76–80 mph range, has become his main strikeout weapon, and he can get hitters to chase it out of the zone as well as freezing hitters with it in the zone. Cahill also features a rare mid-80s slider against righties, though it is a below average pitch.