Sulley Muntari's agent claims Sunderland will not try to sign the Ghanaian midfielder on a permanent basis because of financial reasons.Muntari has struggled to impress since joining the English side on loan from Italy's Inter Milan in January.His agent Fabien Piveteau said: "There is no chance at Sunderland for Sulley. They have decided he is too expensive."But Piveteau, who also represents Ghana's John Mensah, is confident the defender does have a Black Cats future. "For John there is a good chance," Piveteau added."The situation with him is that if he played 25 games he would definitely sign for Sunderland but he has only played 18 at the moment." "He has not played all of the games but it has been a different type of injury this season for John."At the moment I think results are the priority, but the coaches will talk with him soon about next season."Mensah is currently in his second loan spell at Sunderland from French side Lyon but his season has again been ruined by injury.Muntari, meanwhile, has failed to score in eight league games for the Black Cats.Source: BBC