The on-loan Manchester United star has impressed in European competition this season with four goals in five games, though he was unable to keep them in the Champions League.
His goalscoring exploits have dropped off in recent months, but Hecking remains wary of the other attacking threats Sporting have at their disposal.
"I don't think we're going to play a special man-marking on Nani," he said. "We will try to play our usual game style.
"We know the qualities of Nani, however I don't think it is possible to shut him down entirely.
"I remind you of the fantastic goal he made at Maribor, when he decided the whole game with just one scene."
Hecking is hopeful his side can reproduce the stunning form that has seen them emerge as Bayern Munich's main rivals for the Bundesliga title this season.
Goals have not been a problem – as Saturday's thrilling 5-4 win over Bayer Leverkusen showed – but Hecking would like to record a clean sheet before heading to Portugal next week.
"With the rule of away goals being counted double, it would be great to have a clean sheet," he added.
"Just look at Shakhtar [Donetsk, who drew 0-0 with Bayern Munich on Wednesday] – they will arrive in Munich with a good feeling, even though they played 0-0.
"Because they have the feeling that they can always score. It's similar for me.
"We have a great team. I can't even remember the last time we didn't score in a match."
