The Memento star is nominated for Best Actor In A Supporting Role for his performance in The Brutalist, while Culkin is up for the same award for his turn in A Real Pain - and Pearce has thrown out his acceptance speech because he's so confident Culkin will win the coveted prize.
When asked about his first ever Academy Awards nomination, Pearce told the Guardian newspaper: "It's funny (being nominated). Not funny that I haven't had one before - just funny to even get one, I reckon. I stop and go, 'Wow, is that - really? OK? That's really happened?'
"I've been nominated for a few of these awards, and I haven't won any! I'm not gonna win! Kieran (Culkin) will win, again."
Asked about planning an acceptance speech, Pearce explained: "I've had one I've thought about for the last three months now - haven't used it once! Nah, I'll just forget it."
Pearce and Culkin face competition for the Best Supporting Actor Oscar from Yura Borisov (Anora) and Edward Norton (A Complete Unknown) as well as Culkin's former Succession co-star Jeremy Strong, who is nominated for his performance in Donald Trump biopic The Apprentice.
Culkin has been enjoying huge success throughout the Hollywood awards season - winning a BAFTA and a Screen Actors Guild Award among others - for his turn in A Real Pain.
When he picked up his SAG Award on Sunday, Culkin admitted he didn't actually have a speech prepared.
The Academy Awards take place in Los Angeles on March 2.