On July 6, 2006, Janik signed as a free agent with the Tampa Bay Lightning.[2] He played his first full NHL season in 2006–07 and appeared in 136 games over two seasons.
Janik was signed as an unrestricted free agent by the Chicago Blackhawks on July 15, 2008; before playing for the Blackhawks, though, he was claimed off waivers by the Dallas Stars for the start of the 2008–09 season on October 2, 2008.[3] He was then claimed off waivers by Chicago on October 8, only to be immediately traded back to Dallas for a conditional draft pick. After appearing in 13 games with the Stars and being used mainly as a reserve defenseman, he was traded to the Montreal Canadiens for Steve Bégin on February 26, 2009.[4] After clearing waivers, Janik was then assigned to affiliate the Hamilton Bulldogs of the AHL. Janik played his first game with the Montreal Canadiens on April 6, 2009, against the Ottawa Senators.
Unsigned by the Rangers, Janik became a free agent and on July 8, 2009, signed a one-year contract with the Detroit Red Wings.[6] After starting the 2009–10 season with AHL affiliate, the Grand Rapids Griffins, he made his Red Wing debut on November 3, 2009, against the Boston Bruins.[7] He played 13 games with the Wings before recording a career high 37 points with the Griffins. On June 10, 2010, Janik was re-signed by the Red Wings to a two-year contract.[8]
On July 12, 2012, Janik signed a one-year contract with Adler Mannheim of the GermanDEL. During the 2012–13 season, Janik contributed with 10 points in 40 games from the Blueline. He was not tendered a new contract offer at season's end.[9]
On November 25, 2013, Janik signed with the San Antonio Rampage of the AHL.[10] After 13 games with the Rampage, Janik's AHL rights were included in a trade to the Chicago Wolves on March 2, 2014.[11]
On July 21, 2015, Janik signalled the conclusion of his playing career upon accepting an assistant coaching position with the Arizona Coyotes AHL affiliate, the Springfield Falcons.[13]