Pu is set to become a free agent after the Blue Jackets failed to issue him a qualifying offer Monday, Brian Hedger of The Columbus Dispatch reports.
Pu was reassigned to AHL Cleveland on Tuesday.
Pu was recalled to the taxi squad from AHL Cleveland on Monday.
Pu was brought in by the Blue Jackets from the Panthers on Thursday in exchange for Markus Nutivaara.
Pu has six points in four games with the Swamp Rabbits of the ECHL.
The Sabres traded Pu, a 2019 second-round pick, a 2020 third-round pick and a 2020 sixth-round pick to the Hurricanes in exchange for Jeff Skinner on Thursday.
Pu agreed to terms on a three-year, entry-level contract with Buffalo on Monday.
Through two games, Pu has scored a goal and two assists and relishing his role as the team's No. 1 center, The Buffalo News reports.