The midfielder has been on-loan at Dutch Eredivisie side Vitesse Arnhem from German outfit Schalke 04.
Annan, 25, played four seasons for Rosenborg before his move to the German Bundesliga in January 2011.
He has impressed for Vitesse who have expressed interest in handing him a permanent deal.
Annan is however remaining coy about reports of a return to his former club where he spent four years.
"But I know nothing about what happens in the summer, my agent is currently working on it."
Annan has two more years left on his Schalke 04 contract and cost Rosenborg a lot of money to get him back.
"We have regular contact with him through that he has a lot of friends in town," says Rosenborg coach Jan Jonsson.
"We cannot fight with the big money leagues but the social well-being and safety can be arguments to convince.''
Annan played for Ghana at the 2012 Africa Cup of Nations in Gabon and Equatorial Guinea.