Eric Filia competed at Cooperstown Dreams Park during N.A.T.C. in 2004 with the Huntington Beach Vikings (CA). One of Eric's accomplishments at Cooperstown Dreams Park is the game-winning RBI he hit in the championship game. His team, the fifth-seed, topped 22nd-seeded OC Juice (CA) 14-13 to clinch the prestigious N.A.T.C. title. In addition to the championship game, Eric's fondest memories include meeting players from throughout the country.

Eric graduated from and played baseball at Edison High School (Huntington Beach, CA). A four-year letter winner, Eric tied one and snapped two school records during his freshman year (2008) – tied batting average (.500) and broke hits (53) and at bats (106). He capped his freshman season with Sunset League Rookie of the Year honors. According to the Huntington Beach Independent, during his sophomore year (2009), Eric made a verbal commitment to play baseball at UCLA (Los Angeles, CA). He is also a three-time Character Coalition Award recipient. He helped is team to three consecutive Sunset League titles, 2009, 2010 and 2011. Eric was named to the Cal Hi Sports All California 1st Team Underclass and Sunset League MVP his junior year (2010) and co-MVP his senior year (2011). He was also named team MVP as a freshman, junior and senior and received first-team Orange County Register All County accolades his junior and senior seasons. During his final high school season, Eric hit .351 with 33 hits, including six home runs, 16 RBI and 26 runs scored. He finished his scholastic career ranked seventh all-time CIF history with 156 hits.

Eric was also a member of the USA Baseball National Trial Teams (16U in 2008 and 18U in 2009 and 2010) and competed with the Babe Ruth gold-medal winning team at the Tournament of Stars in Cary, N.C.

Following his high school graduation in 2011, Eric played with the Wenatchee Apple Sox of the West Coast Collegiate League before heading off to UCLA to begin his collegiate career. He was selected to play in the league's All-Star game and helped his team finish in first place of the East Division.

Eric made 14 starts and played in 20 games during his freshman season (2012) at UCLA, recording a .245 batting average, eight RBI and 6 runs. He spent the summer of 2012 with the Wisconsin Woodchucks of the Northwoods League. Eric was named to the Northwoods League Post-Season All-Star team with a .383 batting average, 6 home runs, 32 runs scored, 37 RBI and 24 stolen bases. Baseball America named Eric the number 10 overall prospect from the Northwoods League.