Shantz’ stock rose dramatically going into the 2004 draft as he shined in the playoffs for the OHL Mississauga IceDogs, leading them to the OHL Eastern Division championship. He was selected for the CHL All-Rookie team.
Drafted 2nd round (37th overall), 2004 by Florida.
2004-05: Playing for Mississagua (OHL), Shantz lost 15 of 22 games and was benched the entire month of January. He had an overall 10-10-4 record on the season, with a 2.84 GAA and .909 save percentage. Shantz was traded to the Peterborough Petes during the offseason.
2005-06: Shantz had a much stronger season playing for Peterborough, where he helped his team earn a trip to the Memorial Cup. In 49 games he owned a 34-13-3 record, with two of his wins coming as shutouts, along with a 2.87 GAA and .915 save percentage. During the offseason he signed his first professional contract.
2006-07: Played his rookie pro season with the Florida Everblades.
2007-08: Shantz alternated with Tyler Plante between the AHL and ECHL. He began with the Amerks, and overwhelmed, was able to win only one game in 12 starts. With a goals-against average over 4.00, and a .863 save percentage, he was demoted to the Everblades, where he performed respectably the remainder of the season.