The first-round pick is in the 2015 NHL Draft and the conditional second-round selection is in 2014. The second-round pick becomes a first-rounder if the Rangers reach the Eastern Conference Final this season. Also, if Callahan signs a new contract with the Lightning, the Rangers would receive Tampa Bay's second-round pick in 2015 in exchange for New York's seventh-round choice in 2015.
St. Louis, the 2004 Hart Trophy winner and 2013 Art Ross Trophy winner, is currently tied for eighth in the League with 61 points (29 goals). The 38-year-old forward has 973 points in 1,041 career games, and four 90-point seasons on his resume.
He has 388 points in 351 games since the start of the 2009-10 season, which is the most points in the League during that span. St. Louis has one year remaining on his contract worth $5.625 million.
Callahan is an unrestricted free agent at the end of the season and his representation was unable to agree to a new contract with the Rangers. He has 11 goals and 25 points in 45 games this season, and represented the United States at the 2014 Sochi Olympics.
St. Louis reportedly requested a trade from the Lightning after originally being left off the Canadian Olympic team. Tampa Bay general manager Steve Yzerman, who was in charge of picking that team, eventually named him as a replacement for teammate Steven Stamkos.
He was also left off the Canadian team for the 2010 Vancouver Olympics, which Yzerman was also in charge of selecting. St. Louis spent most of the 2014 tournament as Canada's 13th forward.
The Rangers had reportedly been negotiating with Callahan's representatives on a new deal. New York had already signed goaltender Henrik Lundqvist and defenseman Dan Girardi, who were also going to be UFAs at the end of the season, to long-term contracts.