The Spaniard believes that the Giallorossi's lack of European commitments give them the upper-hand going into the upcoming semi-final between the two sides
The Partenopei booked their place in the last four as Gonzalo Higuain's late goal secured a 1-0 win over Lazio on Wednesday at the San Paolo.
But Benitez feels his team are at a disadvantage when they play Rudi Garcia's side over two legs due to their Europa League exertions.
"Roma are a very strong side and have an advantage, as they only need to play one game per week," he told reporters.
"They are not stronger than Napoli, but it makes a huge difference preparing games in two days or in six."
Reflecting on the quarter-final clash, the Spaniard was full of praise for the opposition, who held out until the very end.
"Lazio showed their strength and their pace, but we deserved the win and continued to play with intensity right to the end," Benitez said.
New signing Jorginho performed well and the former Liverpool and Chelsea boss feels the Brazilian can be a vital part of the team going forward.
He added: "Jorginho had a good game. He is the kind of player who can help us change attitude during a match and that is important."
Napoli's next game is a Serie A trip to Atalanta on Sunday, with kick-off scheduled for 15:00CET.