Backstage, he told Movieline that he doesn't understand the fuss over the dog.
Fans of the scene-stealing Jack Russell Terrier who played opposite Jean Dujardin in the silent film demanded for him to attend the Oscars, although Academy Awards officials say that he will not be present.
However, Plummer jokingly hinted that he believes Cosmo, who plays Ewan McGregor's dog in Beginners, deserves the right.
"I think our Cosmo was much more human than Uggie. Uggie was just a trickster. Our dog had soul," he said.
Plummer earned a 'Best Supporting Actor' win at the Independent Spirit awards ceremony for his role as a father who comes out to his son at an old age.
He is also up for a award at tonight's Oscars, which will be hosted by Billy Crystal.
Watch Christopher Plummer in the trailer for Beginners below: