Trevor Bell was a member of the 1999 Week 10 championship team, the Glendale Knights (CA). Trevor helped the Knights earn the title when he hit the infamous two-run home run after the opposing pitcher intentionally walked Amanda Peek, preventing her from tying the home run record (it was 15 at the time). His third at bat, first pitch, Trevor sent the ball out of the park for the round tripper. The top-seeded Glendale Knights posted an 8-5 victory over sixth-seeded North County Flame (CA). Trevor finished the week with 12 home runs and a .583 BA.

Trevor's playing career continued after his week at Cooperstown Dreams Park. At 14, Baseball America named him the best 14-year-old player in the country. A talented pitcher, Trevor was named MVP three out of four years he played on the varsity baseball team at Crescenta Valley High School (La Crescenta, CA). During his junior season, Trevor was 4-4 with a 1.48 ERA with four walks and 97 strike outs. He batted .465 with five doubles, two triples, eight home runs and 30 RBI in 17 games and was named to the All-CIF Southern Section First Team. His final high school season, Trevor posted an 8-3 record with a .97 ERA, 113 strike outs and 11 walks. He also hit .367 with eight home runs and 20 RBI. The team won the CIF Southern Section Pacific League title. Along with MVP honors, Trevor was named as a third-team member of the High School Preseason All-America team by Baseball America as a left-handed-hitting designated hitter.

When Trevor graduated from Crescenta Valley High School in 2005, he held school career records for wins (24), strike outs (317) and home runs (26). Trevor made the leap from high school to professional when he was selected 37th overall by the Los Angeles Angels of Anaheim during the first round of the 2005 Major League Baseball Amateur Draft. Trevor's professional career started in 2005 with the Angels rookie club team Arizona League Angels (Mesa, AZ). In 2006, he played for Orem Owlz (Orem, UT). In 2007, Trevor pitched for the Cedar Rapids Kernels (Cedar Rapids, IA). Trevor began the 2008 season with Cedar Rapids; however, he spent the majority of season at Rancho Cucamonga Quakes (Rancho Cucamonga, CA). The 2009 season started at double-A Arkansas Travelers (North Little Rock, AR). Trevor made his Major League debut on the mound for the Los Angeles Angels of Anaheim on August 12, 2009, versus Tampa Bay Rays. In 2010, he spent three separate stints with the Angels.