Reina spent last season on loan at Napoli from Liverpool, firmly establishing himself as the Serie A club's number one keeper as they finished third in the league and won the Coppa Italia.
Benitez is a firm admirer of the 31-year-old, having first signed him in 2005 when he was Liverpool boss, and Reina - currently away with Spain's FIFA World Cup squad - is expected to bring his nine-year association with the Anfield outfit to an end this close-season.
However, Benitez has indicated that his compatriot's future does not lie in Naples due to financial issues.
"Pepe has two years left on his contract at Liverpool," the former Valencia, Inter and Chelsea manager told talkSPORT.
"He has to go back and he'll stay there - we can't afford Pepe's wages.
"The Premier League is a very big league and, in Serie A, we don't pay big wages like in England.
"He will have to fight for his position at Liverpool."
