Following his career with the Western Hockey League's Lethbridge Hurricanes, he was drafted in the third round, 48th overall by the New York Islanders in the 1991 NHL Entry Draft. After multiple years playing for minor league affiliates in the American, International and East Coast Hockey Leagues, McLennan backed-up veteran Ron Hextall in the 1993–94 season. He was shaky with the Islanders however, winning only 17 games with a .889 Save% over three seasons. Struggling to find confidence, McLennan spent his last two seasons in the organization alternating between the NHL club and the minor leagues.
A few weeks after the 1995–96 NHL season had been completed, McLennan drove from Salt Lake City, Utah to Lethbridge, Alberta, on his way home to Edmonton. While visiting family in Lethbridge he fell ill. He went to a hospital on May 6, 1996, after feeling sick all evening, with immobility setting in. What was thought to be the flu turned out to be bacterial meningitis. After nearly dying that day, he spent the following week in intensive care. The Islanders declined to renew his contract at the conclusion of the season.
The St. Louis Blues signed him to a contract that summer and he spent the following season in the minors. He returned to the NHL as the Blues' back-up goalie for the 1997–98 NHL season. That year he was awarded the Bill Masterton Memorial Trophy, awarded to the NHL player who best displays perseverance and dedication to hockey. In the 1999 off-season, the Blues acquired another backup goaltender, Roman Turek from the Dallas Stars, who easily won the Blues starting goaltender role.[1] With the emergence of Turek and reduction of McLennan's games, the Blues won their first President's Trophy in franchise history.[2] Turek was subsequently awarded as the sole winner of the William M. Jennings Trophy at season's end.[3] That off-season, McLennan was left unprotected by the Blues in the 2000 NHL Expansion Draft and joined the Minnesota Wild franchise. In his only season playing for the Wild, he set a career high in games played with 38, but finished with 32 losses and only 5 wins. Ultimately, he returned to the minors the following season.
The Calgary Flames acquired him in a trade for a pick in the last round at the 2002 NHL Entry Draft[4], where he again played the role of NHL backup goalie, but only won 2 games that year. Despite his timid performances, he remained with the team, once again as Roman Turek's backup for the following season. When Turek became injured in the 2003–04 season, McLennan was thrust into the starting role. He did not stay long however, as the newly acquired Miikka Kiprusoff soon took over the starting role, reversed the team's fortunes, and led the Flames to their first playoff berth in 8 years. Turek returned later thus making McLennan expendable. With the Flames looking to add extra grit to the lineup, they traded McLennan in a package deal to the New York Rangers in March 2004.[5]
Seeking an astute goaltender to partner with highly touted rookie Henrik Lundqvist, the Rangers signed free agent Kevin Weekes to replace McLennan.[6] He then signed a two-year contract with the Florida Panthers, who were seeking a goalie that would only play sparingly with Roberto Luongo. After the Panthers declined their contract option for McLennan the next season, he was brought back to Calgary in 2006 to backup Miikka Kiprusoff.
On April 21, 2007, McLennan entered a first-round playoff game versus the Detroit Red Wings to provide relief to Kiprusoff. Immediately after entering the game, McLennan slashed Johan Franzén twice in the leg. Unable to maintain his cool, McLennan violently slashed Franzén in the stomach a third time after play was stopped, earning a game misconduct, and forcing Kiprusoff to return to the net.[7] The NHL suspended McLennan for five games and fined coach Jim Playfair $25,000 and the team $100,000 for their actions late in the game.[8] As he never played in the NHL again, he remained under suspension after his retirement.[9]
That off-season, he signed with Metallurg Magnitogorsk of the Russian Super League but the team released him after 5 weeks due to poor performances and dislike from management and players.[10]
On July 10, 2008, he was added to the Calgary Flames front office staff as a professional scout.[12] On June 23, 2009, McLennan moved into the coaching staff of the Flames after he was named as assistant to the head coach Brent Sutter.[13]
