Celtic have made just one signing this summer so far – Colombian striker Camilo Duran from Qarabag for an undisclosed fee.
They remain short of centre-forward options ahead of the new season amid uncertainty over the future of Japan international Daizen Maeda, who is entering the final year of his contract.
Former Manchester City and Leicester City forward Iheanacho hit nine goals for Celtic last season having joined as a free agent after the summer transfer window closed.
He missed a chunk of the season with a hamstring injury and only started two games after October.
However, he scored six goals coming off the bench as Celtic won their final nine games to clinch the double.
