Kreider, who is in the final year of a four-year deal worth just over $18 million and is set to hit unrestricted free agency on July 1, will almost certainly be dealt before the deadline if an extension can't be reached.
New York, at 26-22-4 and with 56 points, is currently nine points back of the Hurricanes for the second Wild Card in the Eastern Conference.
LeBrun reported Tuesday that eight teams have Kreider at the top of their wish list, adding that the Blues could be an ideal partner for the Rangers in a potential scenario where St. Louis sends a 2020 first-round pick and center Jordan Kyrou to New York.
Kreider, 28, has spent his entire eight-year career with the Rangers, notching 152 goals and 156 assists in 511 games.
He has 19 goals and 18 assists in 51 games this season as he has been a strong contributor for a New York team that has seen free agent signing Artemi Panarin explode for 27 goals and 44 assists in 51 games to help keep them on the outer edge of playoff contention.
With the Rangers not seeming ready for prime time but with their window of contention possibly opening as soon as the 2020-21 season, a still 29-year-old Kreider would be a tremendous piece to sign long-term. But if that extension can't be reached, Kreider's days as a Blueshirt appear to be numbered.