However, German World Cup-winning centre back Shkodran Mustafi, who has a hamstring strain, is just one of the La Liga club's casualties along with forwards Rodrigo, Alvaro Negredo and Pablo Piatti and defender Antonio Barragan.
"We have some players missing but those of us who are here, I believe we have solutions and the players who will feature are prepared and motivated," Nuno told a news conference on Monday.
Nuno has been under pressure this season as Valencia have failed to find any consistent form either in La Liga or in Europe's elite club competition.
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The demanding fans at the Mestalla expressed their frustration again on Saturday when their team were held to a 1-1 draw at home to promoted Las Palmas that left them in seventh in La Liga after 12 matches.
They face a tough task in Russia on Tuesday against a Zenit side inspired by Brazil forward Hulk, who has netted three goals and assisted four in four outings this term.
Zenit are the only team with a 100 percent winning record in this season's group stage having made their best start to a Champions League campaign with four wins.
Valencia's Spain forward Paco Alcacer said one key to Tuesday's clash will be to snuff out Zenit's swift breaks.
"Zenit have a very good counter-attack and we have to play the way we know," Alcacer told reporters. "We want the ball and we have to be effective up front."
Valencia host Lyon and Zenit play at Ghent in the final round of matches in the group next month.
(Writing by Iain Rogers in Madrid, editing by Rex Gowar)
