Rusev is preparing to make a statement against The Undertaker at the Greatest Royal Rumble event on April 27.
Speaking to TMZ Sports, the former WWE United States champion said he intends to beat the Undertaker so badly in their casket match that the phenom may choose to end his wrestling career.
"Undertaker is a little bit in the past," Rusev said, adding later, "I'll beat him so bad it may be his last fight."
Rusev also had support from his wife, fellow WWE Superstar Lana, who said her husband will "crush" the Undertaker because he is "stronger and faster and better."
WWE announced on Tuesday that Undertaker would challenge Rusev in a casket match at the special event in Saudi Arabia. It will be the Undertaker's first non-WrestleMania match since he took part in the 2017 Royal Rumble.
Undertaker made his return to WWE on Sunday, defeating John Cena at WrestleMania 34. Rusev was pinned by Jinder Mahal in a Fatal 4-way match for the U.S. title that also featured Randy Orton and Bobby Roode on the same show.