McDermott was not selected in the 2000 NFL draft and was not signed by any team afterwards, so he spent the 2000 season completing his college degree and working part-time as a bartender and bouncer.[3]
After sending a highlight video to various NFL teams, McDermott was signed as an undrafted free agent by the Tampa Bay Buccaneers on June 4, 2001.[3][1] He played at long snapper in all 16 games for the Buccaneers in 2001. In 2002, he was signed by the upstart Houston Texans in the 2002 NFL expansion draft and again played at all 16 games at long snapper.[1] McDermott played in the first five games of the 2003 season for the Miami Dolphins before being released on October 14 in favor of Jeff Grau.[4] On December 10, 2003, McDermott signed with the New England Patriots. He played one game before being placed on the injured list December 17.[5] The Patriots would win Super Bowl XXXVIII.