It's not clear what the Blues will receive in exchange for Guerin, one of the biggest names still on the market heading into today's 3 p.m. ET trade deadline. Guerin is making US$2 million this season and will become an unrestricted free agent July 1. The 36-year-old Guerin has recorded 28 goals and 19 assists in 61 games this season.
In 1,010 career games with New Jersey, Edmonton, Boston and St. Louis, he has collected 356 goals and 354 assists.
It's the second big move for the Blues in the last few days. On Sunday, they traded forward Keith Tkachuk to Atlanta.