The Swede signed a four-year contract at the Stadium of Light after signing for an undisclosed fee from IFK Gothenburg, on Wednesday.
 
And he is itching to begin preparations for the new season.
 
"It feels great (to join Sunderland)," he told the club's official website. "I looked at the facilities today and it's a great club.
 
"I love the Premier League, it's the best league in the world. Sunderland is a big club in England so it wasn't a hard decision.
 
"I've come to a club with great players, I can train with great players and good managers, so I think it's a good step.
 
"I want to train hard and be a better player. I want to be as good as I can. I already can't wait, to be here and look at the facilities and the training ground, my legs want to move and play football."
 
Karlsson was part of the IFK side that won the Swedish Cup last season, and he wants to earn more honours at his new club.
 
He also paid tribute to manager Paolo Di Canio, for steering the club to Premier League safety.
 
He added: "It was brilliant, it meant a lot to win trophies. I play football to win trophies, so it's a great experience.
 
"He (Di Canio) came when the club was in crisis and he helped the club to play in the Premier League this season too. He's a good manager."