Mattacchione is a graduate of Father Michael Goetz Secondary School in Mississauga, Ontario. He played with Dixie Soccer Club at the youth level, and after played college soccer for the University of Alabama at Birmingham, where he was the team captain from 1995 till 1997. At Alabama he was named First Team Rookie All-Conference in 1994. He was a 2-Time UAB Team MVP in 1996 and 1997. In 1999, Mattacchione was drafted by the Toronto Lynx of the USL A-League. He recorded his first professional goal on May 30, 1999 against the Jacksonville Cyclones in a 3-2 defeat. The following season, he helped Toronto qualify for the postseason for the second time in the club's history. Toronto would finish third in the Northeast Division. In the playoffs the Lynx faced Richmond Kickers in the first round, and advanced to the next round by a 3-1 goals on aggregate. In the next round Toronto would face the Rochester Rhinos, but would be eliminated from the playoffs by a score of 2-1 on goals on aggregate. At the conclusion of the A-League 2000 season he signed with the Toronto ThunderHawks of the NationalProfessional Soccer League. During the winter indoor season he appeared in 13 matches and scored one goal. Mattacchione was re-signed by the Toronto Lynx for the 2001 season. During the 2001 season he appeared in 25 matches and recorded three goals. On April 17, 2002 Mattacchione signing was announced in a press conference which revealed the team roster for the 2002 season. He was awarded the club's Best Defensive Player award on August 30, 2002. During the 2002 winter season he had a stint with Cleveland Force, and appeared in 31 matches and recorded two goals. He returned to Toronto on April 28, 2003. During the 2003 season he saw limited action due to a foot injury, but still managed to achieve a franchise record by being named to the A-League Team of the Week six times throughout his career. In 2005, under new head coach Hubert Busby, Jr. Mattacchione succeeded Shawn Faria as the new club captain. On April 26, 2006 would retain his captaincy and be given the dual role of player/assistant coach under Duncan Wilde. During the 2006 season he helped the Lynx to a team-record of a 10-game undefeated streak at home, and also helped the Lynx reach the final of the Open Canada Cup which they lost 2-0 against Ottawa St. Anthony Italia. Subsequently, after the 2006 season the Lynx dropped two divisions down into the PDL, thus making Mattacchione a free agent after which seven seasons with the club he was ranked in the top five for all-time games and minutes played for the Lynx. After retiring from soccer, he was appointed the U12 Development Director for the Oakville Soccer Club in 2007, and become a high school careers and gym teacher at his old high school Father Michael Goetz.
