The highly-anticipated Comedy Central roast of country legend Willie Nelson has been postponed indefinitely, the network confirms. Scheduling conflicts, including Nelson's upcoming European tour, have forced the network to reconsider the airdate (originally slated for April 17); a new date has yet to be determined. The roast would have preceded Nelson's 75th birthday on April 30 and coincided nicely with the release of One Hell of a Ride, a four-CD boxed set chronicling 50-plus years of recordings (due April 1). Nelson is currently in New Mexico filming Beer for My Horses, a movie starring Toby Keith that shares the name of his No. 1 country hit. Nelson plays a circus ringmaster opposite David Allen Coe. Other noteworthy cast members include rocker Ted Nugent and actress Gina Gershon.