Poyet snapped up the 27-year-old as a free agent last month after he was released by Manchester City, where Pantilimon made 29 appearances in three seasons as Joe Hart's understudy at the Etihad Stadium.
Vito Mannone started 28 of Sunderland's 38 Premier League games last term and Pantilimon insists he has not moved to the Stadium of Light to be a squad player.
"We are different keepers but we both have good skills, I have my qualities and Vito has his own but we will both work hard to improve," Pantilimon told the club's official websites.
"It is good for club's to have two good goalkeepers and it is normal for everyone to work hard for a place in the team, so we will both fight for the position."
Pantilimon has settled quickly in his new surroundings and wants to play a part in ensuring that Sunderland improve after the club avoided relegation following a late-season upturn in form last season.
He added: "From the moment I arrived I have enjoyed everything, I like what is happening in the team and I like the people.
"I hope to do better than last season because it was a difficult year, I hope to win more games and have a good position when the Premier League ends.
"I know all about what has happened in the past, I was talking with a few people and the club have had a lot of good goalkeepers."
