Trade talks concerning New York Rangers captain Ryan Callahan continue to escalate, with a new development coming to light Friday night. A source confirmed to ESPNNewYork.com that the Rangers have granted permission for Callahan's agent, Steve Bartlett, to speak with other teams regarding the pending unrestricted free agent, as earlier reported by TSN.

TSN reported that at least one team already has spoken with Bartlett, although a source told ESPNNewYork.com on Friday night that the Rangers remain the only team with which Callahan's camp has had substantive discussions about a contract extension.

Approached after the Rangers' 4-1 win over the Islanders on Friday night, Callahan said he was unaware of the recent reports.

"I didn't hear about it," he said. "My heart's here. I want to be here. That's all I worry about on the ice."

According to ESPN.com's Pierre LeBrun, the Columbus Blue Jackets are one team that has expressed interest in the gritty 28-year-old winger, who is in the last year of a three-year, $12.825 million deal that comes with an annual $4.275 million cap hit. TSN also reported the St. Louis Blues are a potential trade partner, with winger Chris Stewart a player the Rangers have been "gathering intel" on recently.

Whether the Rangers have fully committed to moving their heart-and-soul leader has yet to be determined -- at least some people with knowledge of the situation remain unconvinced the Rangers have given up on trying to re-sign him to a multiyear deal -- although it appears the contract discussions are at an impasse.

"I'm a big fan of Ryan Callahan and I know he wants to be here. Contracts have nothing to do with me, but I'm hoping both parties can come to an agreement," coach Alain Vigneault said after Friday's game.

The Rangers made an offer of a five-year deal worth $30 million, though it is believed Callahan is still seeking a seven-year deal at that annual salary, multiple sources told LeBrun.

However, the Rangers are believed to be uncomfortable with that contract length given Callahan's durability issues.

The Rochester, N.Y., native has missed time with three separate injuries already this season, which raises an interesting question: If the Rangers want to trade him, do they want to do so before the Olympic break roster freeze?

Doing so would hedge against the possibility of Callahan suffering an injury while playing for the U.S. team in Sochi and could give the Rangers at least one extra pay period of cap relief, depending on what they are seeking in return.

The New York Post reported Friday that the Rangers would like to make a decision either way before the Olympic break, although two people with knowledge of the situation told ESPNNewYork.com that they were not aware of any such deadline.

Injury concerns aside, Callahan's intangibles have been invaluable during his tenure with New York, as his teammates were happy to attest.