Last week, the Academy of Motion Picture Arts and Sciences announced that Cooper and Lady Gaga will take to the award ceremony’s stage to perform a duet of the Oscar-nominated song Shallow, from their movie, A Star is Born.
Speaking with E! News, Cooper said, “I’m sure I’ll be terrified.”
The Hangover actor also admitted that he was nervous when he took the stage with Lady Gaga in Las Vegas for their first live performance of the song in front of an audience.
“That was terrifying,” Cooper said. “I just had to zen out and just pray that I wasn’t going to ruin her show. Just think about it? She just crushed it for two hours and I’m just thinking, ‘Please let me be on pitch.'”
WATCH BELOW: Lady Gaga invites Bradley Cooper on stage for surprise duet in Las Vegas
According to Variety, Cooper was in the audience enjoying the show before he shocked fans by jumping onstage for the final number.
“I even got you in-ears,” Gaga told Cooper after the two embraced, describing the earphone-like monitors used onstage.
“I can’t hear anything,” he joked, telling the crowd, “Hello Vegas,” before singing his verse in the Oscar-nominated song.
After their performance, Gaga’s backup dancers took their bows, with Cooper joining them. “Bradley, thank you,” said Gaga, with Cooper then tossing his baseball cap into the audience.
Cooper is nominated for two Oscars: Best Actor and Best Adapted Screenplay.
Lady Gaga is nominated for Best Actress, while Shallow is nominated for Best Original Song.
A Star Is Born was also nominated in the Best Picture category.
The 2019 Oscars airs live Sunday, Feb. 24, at 8 p.m. ET/PT.
Watch the Las Vegas performance in the video above.
— With files from ET Canada