Chico was selected by the Arizona Diamondbacks in the third round of the 2003 amateur draft. Chico began the 2006 season pitching for Lancaster of the high Class A California League, where he accrued a 3-4 record and a 3.75 ERA in 10 starts. He was promoted to the Tennessee of the Class AA Southern League, accumulating a win-loss record of 7-2 and an ERA of 2.22 in 13 starts.
On August 7, 2006, the Washington Nationals acquired Chico and fellow minor league pitcher Garrett Mock from Arizona in a trade for veteran right-handed pitcher Liván Hernández. After joining the Nationals organization, Chico pitched for the Harrisburg Senators of the Class AA Eastern League, winning 2 and losing none of his first 4 starts and compiling a 3.27 ERA. At the end of 2006, Chico had earned a spot on the Nationals' 40-man protected roster. Coming out of 2007 spring training, Chico had made the club's starting rotation, and he made his major league debut on April 4, 2007, at RFK Stadium versus the Florida Marlins. His first major league win came on April 16, in a Nats 5-1 victory over the Atlanta Braves. Chico got off to a rocky start, on a cold and bitterly windy night, walking the bases loaded in the first inning, but escaping unscathed. He went on to pitch five innings, before walking two in the sixth and getting relieved, allowing just one run. During his next start, at Florida on April 21, 2007, in the bottom of the first inning, Chico attempted to throw a changeup to Josh Willingham. He missed the plate badly; the ball sailed over the first-base dugout. Chico ended up becoming a mainstay for the Nationals in the first half of the season. By Mid-May, four of the Nats' five starting pitchers were out with injuries, but by July 4, Chico had not missed a turn, and was second in the league with 18 starts. From June 23 to July 4, he pitched 20 innings allowing only one run. He ended the 2007 season with a 7-9 record and an ERA of 4.63 over 167 innings. Chico emerged as the Nationals' #2 starter at the beginning of the season. However, he struggled to an 0-6 record in eight starts and three relief appearances, and was optioned to the Class AAAColumbus Clippers on May 23. After he pitched only one game for Columbus, an MRI examination in early June revealed loose bodies in his throwing elbow. On July 3, 2008 Chico underwent elbow reconstruction surgery. He missed the rest of the 2008 season and most of the 2009 season. He returned to the major leagues on May 8, 2010 when he tossed five-plus innings and allowed two earned runs to the Florida Marlins at Nationals Park while giving up six hits, striking out three and walking none but did not get a decision. A day after pitching, Chico was designated for assignment on May 9 but remained on the 40-man roster and was sent down to the Double-A Harrisburg Senators.
On June 18, 2012, the York Revolution of the Atlantic League announced they had signed Chico. After making 6 starts Chico was released going 1-3 with a 7.50 ERA.
