The Naples outfit resume their Serie A campaign at home to Roberto Donadoni's charges on Saturday, before travelling to the Signal Iduna Park to square off with Dortmund.
Napoli - who sit second in Group F - currently lead last season's Champions League runners-up by three points, and will secure their progress to the round of 16 with a win.
But head coach Benitez refused to look beyond the Parma game as he looks to restore Napoli back to winning ways in the league following a 3-0 reverse against reigning champions Juventus last time out.
"The next game is always the most important," he said. "We're thinking about Parma and my team selections will be based on that tie and not the Dortmund one.
"All of my players are focused and ready, then we'll see what we do against Parma. But I have really liked what I saw in training.
"I've obviously watched the 3-0 defeat to Juve again. We gave them too much space in the opening minutes."
Ahead of the clash, Benitez highlighted Antonio Cassano as Parma's biggest threat but is wary of sevral others who can hurt his side.
He added: "The quality of Antonio Cassano is clear to everyone. He is a dangerous player who we will have to be aware of.
"Parma also have Jonathan Biabiany and his pace is dangerous, as well as Amauri.
"They have players who work well in the defensive phase and who are good on the counter."
Napoli have amassed 28 points from 12 Serie A fixtures this season, a return which has guided the team to third place.
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