2000–01 Eaton made his major league debut for the Padres on May 30, 2000, against the
Milwaukee Brewers, and
won his first major league game. He went 7–4 in the season, striking out 90 in 135 innings, and posting a 4.13 ERA. Eaton did not lose in his first eight starts as a Padre, posting a 1–0 record with a 3.02 ERA. He posted the best day game ERA in the National League (2.34), and became the third Padres pitcher, after
Juan Eichelberger and
Doug Brocail, to
steal two bases in a single season. His
batting average (.289) led all major league pitchers. and underwent season-ending
"Tommy John" surgery on August 21. Before his injuries, Eaton posted an 8–5 record with a 4.32 ERA. This season also produced his first two career complete games, and he posted two ten-strikeout games against the
Houston Astros and the
San Francisco Giants. Eaton's ERA was a career low (4.08), but he only managed a 9–12 record over his second full season. He pitched at least seven innings in ten of his 31 starts, including a season-high eight innings to earn his third complete game of his career against the
Cleveland Indians. Though he started the season weakly, July was Eaton's top month; he posted a 4–0 record and a 2.81 ERA in the month. His nine wins were a career high.
2004–05 was a career year for Eaton, as he reached new levels in wins, with 11; starts, with 33; innings pitched, with ; and strikeouts, with 153. He beat the
Los Angeles Dodgers, a San Diego rival, four times during the season, posting a 4–1 record and a 2.87 ERA against them. He also won eight games on the road, posting a 2.66 ERA during his seven-game winning streak away from new
Petco Park. but he went on the disabled list in the middle of June with a strained finger.
2006 After the trade, Eaton was penciled in as the number two starter for the Rangers going into the season. However, during a
spring training game on March 29, Eaton injured his right middle finger, causing him to go on the 60-day
DL and miss the first half of the season.
Signs with Phillies On November 27, 2006, Eaton signed a three-year deal worth $24 million to re-join the team that drafted him, the Philadelphia Phillies.
2007 Eaton made his debut for the Phillies on April 5,
2007 against the
Atlanta Braves. He pitched innings giving up 7 earned runs and took the
loss. Eaton was the losing pitcher of record when the Phillies lost their 10,000th game in franchise-history on July 15, 2007, to the St. Louis Cardinals, 10–2, marking the first time a professional sports franchise reached that plateau. Eaton was 10–10 with an earned run average of 6.29, one of the worst in the league; despite this, the Phillies won the National League Eastern Division for the first time since . However, Eaton was not included in the postseason roster.
2008 Eaton's performance with the Phillies in the first half of the season was also decidedly poor; through July 12, he notched a 3–8 record in 19 starts with an earned run average of 5.71. His last two outings before the
All-Star break were a prime example; he yielded a combined 17 hits and 14
runs in 6 innings against the
New York Mets and
Arizona Diamondbacks. It was announced on July 18 that Eaton would lose his spot in the Phillies' rotation to newly acquired
Joe Blanton. Eaton was optioned to the minor leagues on July 28, 2008. He did not return to the majors until he was added to the September callups as a bullpen pitcher. He did not appear in any game after his callup.
2009 Two days after he was released by the Phillies, Eaton signed a minor league contract with the
Baltimore Orioles on March 1, 2009. In an interview with
MLB.com after his release from the Phillies, he claimed he was partially responsible for the Phillies' success in
2007 and
2008: "A lot of things went wrong, but [there were] a lot of things that went right, too. I helped them get to the playoffs two years in a row, and obviously we won the
World Series last year." He was promoted to the Orioles after spending the first week of the 2009 major league season with the
Norfolk Tides. He was released on May 22 after going 2–5 with an 8.56 ERA in eight starts.
Colorado Rockies On June 6, Eaton signed a minor league contract with the
Colorado Rockies. On September 9 he was
designated for assignment. Eaton was granted free agency on October 6, . ==References==