Barnes was drafted in the second round, fifty-fifth overall in the 1998 NHL Entry Draft by the Detroit Red Wings. Barnes played his junior career for three teams in the OHL; the Sudbury Wolves, the Toronto St. Michael's Majors and finally the Barrie Colts. On October 3, 1999, he was suspended from the OHL for 25 games for a stick-swinging incident in a game against Oshawa Generals. Due to this incident, he was placed under house arrest, only allowed to leave his billet's house to work out. At the end of that season, he played with the Barrie Colts in the Memorial Cup Championship final.
He tested his coaching abilities for the first time for the 2007-2008 season with the Port Colborne Sailors, now known as the Port Colborne Pirates, in the Greater Ontario Junior Hockey League. Ryan has been hired to work as an assistant coach with the Peterborough Petes for the 2008-09 season.