Letestu will head to AHL Cleveland having cleared waivers Friday, Aaron Portzline of The Athletic reports.
Letestu agreed to terms on a one-year, two-way contract with Columbus on Thursday.
Letestu was cut by the Panthers on Monday.
Letestu signed a deal for a professional tryout with the Panthers on Tuesday.
Letestu scored a goal in the first period of Monday's 5-1 win over the Capitals.
Letestu (not injury related) will be in the lineup Monday against the Capitals, George Richards of the Columbus Dispatch reports.
Letestu is hoping to finalize his work visa ahead of Monday's matchup with Washington, Tom Gulitti of NHL.com reports.
Letestu was traded Sunday from Edmonton to Nashville in exchange for Pontus Aberg, and then traded from Nashville to Columbus for a 2018 fourth-round draft pick.
Letestu will be a healthy scratch for Thursday contest against the Flames, Jack Michaels of the Oilers Radio Network reports.
Letestu scored a short-handed goal and added an assist during Tuesday's 7-2 rout over the Blue Jackets.