Alvaro Negredo has again been left out of Valencia's matchday squad as they prepare to take on Gent.
The former Manchester City striker, who has scored just twice so far this season, sat out Saturday's 3-0 victory over Malaga and has been overlooked for Tuesday's Champions League encounter.
Negredo stressed earlier this month that there are no issues between him and head coach Nuno Espirito Santo despite his struggle for form at the Mestalla, and Nuno is adamant the decision is simply a "technical" one.
"All the decisions we've made are based on technical, sporting reasons," he said. "It's a long season, there are lots of competitions and every player will be important in the end.
"It is my obligation to get the best out of all the players in my squad and look for ways to improve. We're not going to give up on that."
Unbeaten in the league this season, Gent held Lyon to a surprise 1-1 draw in their Group H opener and Nuno expects a stern test as Valencia chase their second win of the group stage.
"Never underestimate the opponent. Never, ever. We respect every opponent," he said.
"Gent have good players and are a compact team. They are very well organised in defence and we know they are going to put pressure on us.
"Our victory in Lyon [on matchday two] was quite important, but these two matches are even more decisive for the future of the group. We have it in our own hands."
Midfielder Sofiane Feghouli admits Valencia have so far been underprepared for the game given they faced Malaga in La Liga late on Saturday.
"We still haven't had time to study the game. But it's the Champions League and they deserve total respect," he said.
"We have a lot of confidence because we won the last game and we hope to do even better with the help of the crowd."
Feghouli is fully confident he will sign a new contract with the club soon, with his current deal set to expire in less than 18 months' time.
"No, because I've wanted to renew since 2014," he replied when asked if there were any concerns over a new deal.
"My agent is negotiating and we'll reach an agreement soon. I'm happy here and I'm giving my very best as a professional."