The Black Cats manager has complimented the top-flight's newest additions by tipping the Welsh side to finish in the top half of the Premier League come May
O’Neill doesn’t expect last year’s Championship Play-off winners to experience the troubled second half of the season that Blackpool endured over the last campaign.
Sunderland will be welcoming a confident Swans side to the Stadium of Light after the Welsh side’s impressive 3-2 home triumph against Arsenal last week.
"They play attractive football and have gained the results to go with that, which gives them a great belief in themselves," O'Neill told the club's official website.
"From that viewpoint, I get the feeling there is a natural exuberance that carries them on a great deal further than perhaps they would expect.”
The former Aston Villa boss also stated that he doesn’t see Swansea and fellow Premier League newboys Norwich City as relegation candidates come the end of the season.
He said: "I suppose you could say that Blackpool were going strongly at this point, but then had a few issues to contend with in the January transfer window where it looked as if some of their top players might leave.
"That caused consternation and I'm not sure they really recovered from that.
"But I don't expect the same thing to happen with Swansea and Norwich at all. They will be looking at the top half of the table rather than the bottom."