The Premier League side could also offer Messi the chance to become an ambassador for the City Football Group.
City are favourites to sign the 33-year-old after he told Barcelona he wants to terminate his contract.
It has since emerged that Messi spoke with City manager, Pep Guardiola, days after Barca lost 8-2 to Bayern Munich in the Champions League.
Although City will try to sign Messi as a free agent, they would also consider paying €100 and €150 million, if he is unable to force an exit unilaterally.
Players like Eric Garcia and Angelino could be included in any potential deal.