The Spaniard feels the ex-Bayern Munich trainer earned the accolade with last season's treble and believes Fiorentina will pose Napoli a real challenge
The Spaniard is on the 10-man shortlist himself, after winning the Europa League with Chelsea last season and then making an impressive start to the current campaign with new club Napoli.
However, Benitez feels that Heynckes, who parted company with Bayern Munich this summer after leading the German giants to a treble, is the obvious choice.
"Jupp should get the award," the former Liverpool boss told reporters on Tuesday. "He won a lot last season with Bayern and is an example as a professional."
Napoli currently sit second in Serie A but are nonetheless five points behind leaders Roma, who have won all nine of their league games to date.
Benitez insists that he always expected the Giallorossi to fight for the title this season but he does think that the pressure of heading the table may yet affect Rudi Garcia's in-form side.
"I said that there were four or five sides who could win the Scudetto at the start of the season," he pointed out.
"Roma were one of those and they will win the championship if they continue like this. But the pressure will mount on them.
"We’ve had a positive start to the season. We have won seven, drawn one and lost one. We’ll see where we end up."
Napoli face fifth-placed Fiorentina on Wednesday night and Benitez is anticipating a very tough test for his side at the Artemio Franchi.
"They are a difficult side to take on," the Spaniard noted. "We will have to keep an eye on Juan Cuadrado, but we will not be man-marking him.
"It is a game that is worth three points like all the others, but it is a significant game as it is between two sides who are high in the standings.
"They are good in possession and they can score goals in numerous ways. We need to keep hold of the ball so we’ll have to wait and see who controls the game.
"But the defensive side of the match will be important too."