The 34-year-old forward has degenerative disk disease of the lumbar spine and likely will not play professional hockey again.
"I don't think a year off or two years off is going to help it to be honest with you," Callahan told the Lightning website. "From what the doctors have said and the way I feel, it doesn't look like I'm going to be able to come back."
Callahan had 17 points (seven goals, 10 assists) in 52 regular-season games and no points in two Stanley Cup Playoff games.
"He's such a proud competitor, such a fierce competitor," BriseBois said. "I know he was planning to not only play out this contract, but sign another contract after that."
Callahan has one season remaining on a six-year, $34.8 million contract ($5.8 million average annual value) he signed with Tampa Bay on June 25, 2014.
"The likeliest scenario now is that we are going to put him on long-term injury exemption and that is how we're going to manage his [NHL salary cap charge] going forward," BriseBois said.
Selected by the New York Rangers in the fourth round (No. 127) of the 2004 NHL Draft, Callahan has 386 points (186 goals, 200 assists) in 757 regular-season games and 39 points (20 goals, 19 assists) in 121 playoff games.
"I've been dealing with some back issues for a couple years now, this year being the worst that it's ever been, obviously missing some games with it, leaving some games with it," he said. "I've kind of been battling it all year. Didn't know to what extent and after the season I went and saw a couple specialists and after talking to them, it wasn't easy to hear what they thought was going on and most likely won't be able to play. It was definitely tough to hear that."
Callahan was Rangers captain from Sept. 12, 2011, until March 5, 2014, when he was traded to Tampa Bay in a deal that sent forward Martin St. Louis to New York.
