McCarthy was drafted by the Chicago Blackhawks with the twenty-third pick in the 1999 NHL Entry Draft. He made his debut in the 1999–2000 NHL season and he recorded an assist on his first shift. After playing 134 games with the Blackhawks, he was traded to the Vancouver Canucks on August 22, 2005 in exchange for a third-round pick in the 2007 NHL Entry Draft. He was then traded to the Atlanta Thrashers by the Canucks for a conditional fourth-round pick. on March 9, 2006