While completing a junior career in the
Western Hockey League (WHL) with the
Prince George Cougars, Mason was originally drafted 122nd overall in the
1995 NHL entry draft by the
New Jersey Devils. Embarking on his professional career and un-signed from the Devils, Mason signed as a free agent by the
Mighty Ducks of Anaheim on June 27, 1997. After his rookie professional season with the Ducks'
American Hockey League (AHL) affiliate, the
Cincinnati Mighty Ducks, and on the eve of his sophomore season, Mason was traded by Anaheim along with
Marc Moro to the
Nashville Predators in exchange for
Dominic Roussel. Mason made his debut in the NHL with the Predators during the
1998–99 season, relieving in three games. After a further three seasons within the Predators organization, Mason left as a free agent and signed a contract with the
Florida Panthers. Mason was assigned to Florida's AHL affiliate, the
San Antonio Rampage, for the duration of the
2002–03 season. He re-signed with the Panthers to a one-year extension, however he never featured for the club before he was claimed in the
2003 NHL Waiver Draft to return to the Nashville Predators. In the
2003–04 season, Mason joined the Predators full-time as the backup to starter
Tomáš Vokoun. In 17 appearances that season, Mason finished with a 4–4–1 record with a 2.18 goals against average (GAA) and .926 save percentage. During the
2004–05 NHL lockout, Mason played for
Vålerenga Ishockey in the Norwegian league with fellow Predator
Scott Hartnell. Being hailed as the best goalie in the league ever, he played a big part in Vålerenga securing their 25th league championship and their 24th Norwegian Championship by winning the playoffs. On April 15, 2006, when he was starting because starting goaltender Vokoun was lost for the year with a blood condition, Mason was credited for a goal when
Phoenix Coyotes forward
Geoff Sanderson shot the puck into his own net. Mason became the ninth
NHL goaltender to score a goal and joined
Damian Rhodes as the only goalies to be credited with a goal in both the AHL and the NHL. In the off-season of 2007, Vokoun was traded to the Florida Panthers for a few draft picks, leaving Mason as the starter for Nashville, alone with backup goaltender
Dan Ellis. Mason quickly won the first two games, the collective scores of which were 9–1 in favor of the Predators, but then dropped a startling seven straight games. Dan Ellis, however, was able to step up for the Predators and win four straight. Mason returned to play against the
Detroit Red Wings in a 43-save loss. The loss was no surprise, but Mason did show that he could effectively remain the Nashville starter, and continued to start for the remainder of his time with the Predators. in the 2008 off-season. On June 20, 2008, Mason was traded by the Predators to the
St. Louis Blues for a fourth round draft pick. In two seasons as the Blues number one goalie, Mason appeared in career high 61 and 57 games, to post 27 and 30 wins respectively. On July 1, 2010, Mason left the Blues and signed a two-year, $3.7 million deal with the
Atlanta Thrashers, marking the first time in his NHL career that Mason played for an Eastern Conference team. Mason's
2010–11 campaign was a disappointment, as it marked the first time in his career that he posted a GAA above 3.00. Following the team's relocation, Mason played out the second season of his contract for the
Winnipeg Jets. On July 1, 2012, Mason returned for a third stint with the Nashville Predators, on a one-year deal to serve as the team's backup goalie. During the
lockout shortened
2012–13 season, Mason was unable to recapture his earlier career form posting a career low goals against and save percentage. With limited NHL interest at season's end, Mason signed abroad in Italy to a one-year contract with
Ritten-Renon of the
Elite.A on August 6, 2013. After a successful season in Italy, on May 23, 2014, he moved to Germany to sign a one-year contract with the
Augsburger Panther of the
Deutsche Eishockey Liga (DEL). On September 21, 2015, Mason announced his retirement from professional hockey and that he would be joining the Nashville Predators Radio Network as a colour commentator for select games during the
2015–16 season. Beginning in the 2017-18 season, Mason became the primary TV commentator for Predators games. ==International play==