New Barcelona signing Kevin-Prince Boateng dismissed suggestions of a past allegiance to Real Madrid and Cristiano Ronaldo by lauding Lionel Messi as the best player "in this world and every world" during his official presentation.

Boateng completed a shock move to Barca on Monday, with the Catalan club bringing him in from Sassuolo on a loan deal until the end of the season which includes an €8million purchase option.

Despite being undoubtedly talented, the 31-year-old represents a left-field option for Barca, considering the level Boateng has been operating at for the last two years.

Before Sassuolo, Boateng played for Las Palmas and then Eintracht Frankfurt, never quite living up to the early expectations of him after impressing as a teenager with Hertha Berlin.

After rumours of his move began to circulate, past quotes from Boateng declaring himself a Madrid fan and praising Ronaldo as the world's best player began to resurface, but he had a concise response on Tuesday.

"I am a Barcelona player and Lionel Messi is the best player in this world and every world," the Germany-born former Ghana international told reporters.

"Why are you laughing? That's the truth, he has shown that with all that he has won in the last 10 years.

"It's a great honour [to be at Barcelona] because Messi is the best player in the world, and Luis Suarez the best striker in the world.

"They play amazingly and being able to play by their side is a great gift."

Boateng is fully aware that he has not been brought in to slot straight into the starting XI, but believes his versatility will serve him well, as he is able to play in midfield and further forward.

"At my age, the number nine role is perfect for me, but for a coach, I think a player like me is a plus because I can play in different positions, but I feel very good as a number nine," the former AC Milan man said.

"I have not talked to the coach [Ernesto Valverde], but I know I have not come to play in the starting line because there are incredible players in this team.

"I'm here because of my experience and to help. I'm here to play well and sign on for more years here, that's my goal."