The Israeli’s two-and-half-year contract officially expired on Tuesday almost a month after leading the team to a fourth-place finish at the 2017 Africa Cup of Nation in Gabon.
“I can tell you that the job of the next Black Stars coach will be very challenging," Osei told Atinka FM.
"This is because Avram Grant has put us in a situation that is difficult for anyone to amend. Grant has jeopardised our World Cup qualification chances and it will be difficult for any coach who takes over the Black Stars to be able to thwart the efforts of our opponents and make it to our fourth consecutive tournament.
"Things look scary for Ghana now because we are five points behind Egypt and the new coach will have to double his efforts to restore the good days. Grant has really jeopardise everything we aimed to achieve so the new coach must do extraordinary things," he added.
Ghana FA have set up a six-member committee to appoint a new coach, with assistant Maxwell Konadu to manage the Black Stars' affairs in the interim.