Chen is of Chinese descent. His paternal grandfather, Kuen Chin Chan Lee, joined his brothers and other relatives in Panama at age 9. Bruce's maternal grandmother, Kuen Yin Liu de Laffo, was born in Panama, but her family had to return to China after fire destroyed their home. After years of hard labor, she was able to return to Panama at age 24. Both of Bruce's grandparents have died, but he hopes to reconnect with his Chinese roots someday. Bruce's older brother, Greg Kateso Chen, is in the minor league affiliate of the Boston Red Sox organization.

Bruce Chen attended Panamerican Institute and studied civil engineering during the baseball off???season at Georgia Tech .

In the Major Leagues, Chen has played for the Baltimore Orioles, Houston Astros, Boston Red Sox, Cincinnati Reds, Montreal Expos, New York Mets, Philadelphia Phillies, Atlanta Braves, Texas Rangers , and the Kansas City Royals.

Orioles

Chen appeared to have turned the corner when he played for the Baltimore Orioles. He added a changeup to his repertoire of pitches, which includes an 87???90 mph fastball, and a slow 12???6 curveball. His 11 starts for the Orioles, from the end of 2004 through the 2005 season, indicated that he was well on his way to fulfilling the enormous potential that made him such a highly regarded prospect earlier in his career ??? but that turned out not to be true.

World Baseball Classic

Chen pitched for Panama in the inaugural World Baseball Classic in 2006, working five innings, giving up four hits, two runs (both earned), and a walk, with three strikeouts, against a powerful Cuba team in the opening round of the tournament at San Juan, Puerto Rico.

2006 season

In 2006, Chen appeared to have regressed. He went 0???7 with a 6.93 earned run average (ERA), starting 12 games, but appearing in 28 others coming out of the bullpen. After pitching for an entire season without a win, the Orioles declined to re???sign Chen, and he filed for free agency on November 1, . Chen signed a minor league contract with the Texas Rangers on February 6, , with an invitation to spring training. Chen made the Rangers' opening day roster, taking a spot in the bullpen. He was reported to have reworked his contract to accept an outright assignment to Triple-A Oklahoma if room was needed on the roster.

While playing for the Phillies, Chen had a loyal group of fans known as "The Chen Pen".

2009 season

On March 1, , Chen signed a minor league contract with the Kansas City Royals. He made his major league debut with the Royals on June 27, 2009. He allowed 4 runs in 7 1/3 innings. Chen's second start was much better, as he only gave up two runs on five hits with one walk and five strikeouts. On August 6th, 2009, Chen won his first major league game since Oct. 2nd, 2005.

2010 season

Chen re-signed a minor league contract with the Royals on December 11, 2009. On April 26, 2010, he earned his first Major League save, in a 3-1 Royals victory over the Seattle Mariners. He threw seven perfect innings before allowing a hit on July 20, 2010 against the Los Angeles Angels.

On October 1, 2010, in his last start of the season, Chen threw a two-hit shutout against the Tampa Bay Rays, striking out seven and only walking two. It was the first shut out he has thrown in his Major League career. He finished the season with a 12-7 record, and an ERA of 4.17.