Last year, Messi and his father, Jorge, were found guilty of three counts of tax fraud.
Both appealed, but Spain's Supreme Court last month confirmed the jail term for the Barcelona striker, although it reduced Messi's father's sentence to 15 months.
However, he was spared serving hard time due to Spanish law denoting that any sentence under two years can be served as probation.
The judge in charge of the case will now make a decision bearing in mind the prosecutor's recommendations.
Tropical Storm Bret forms in Atlantic off Venezuelan coast
Tropical Storm Arlene formed back in April, almost two months before the formal start of hurricane season on June 1. Tropical Storm Bret has formed in the Atlantic Ocean off the coast of Venezuela.
The fine-for-time deal was presented by Messi's lawyers to the judge who will rule on whether to suspend his sentence - as is widely expected - state prosecutor Isabel Lopez Riera said.
The shocking revelation comes just days after reports emerged that Cristiano Ronaldo is desperate to leave Real Madrid after he too was accused of tax evasion by Spanish prosecutors.
Messi and his father defrauded the Spanish tax office of 4.1 million euros between 2007 and 2009 by using a web of shell companies based in Belize, Switzerland and Uruguay to evade taxes on income from the player's image rights.
However, Spanish news agency EFE reported on Friday that the public prosecutor has agreed to substitute the sentence for a fine of €255,000.