If this fixture had been a few weeks ago Kuban would have found a Valencia side under all sorts pressure, having lost three successive Primera Division matches and also been humiliated 3-0 at home by Swansea in their Europa League Group A opener.
At that stage there was speculation about the job security of Valencia's newly-installed coach Miroslav Djukic, but since that loss to the Welsh side Los Che have rattled off three consecutive league wins to climb up to sixth in La Liga.
And Dealbert, who helped Valencia to three successive third-placed finishes during his time at the Mestalla between 2009 and 2012, believes the confidence has now started to return to his old club.
He told Efe: "It's a morale boost (for them). Three weeks ago there were problems, but now, after three successive wins, they will be much calmer.
"I know them very well. Valencia have some very technical players, like (Sergio) Canales, (Andres) Guardado and (Sofiane) Feghouli, who when they have confidence turn them into a very dangerous team.
"Valencia have, possibly, the fourth best squad in Spain, after Barcelona and Real Madrid, and because Atletico Madrid are now in great form. If they weren't, then they (Valencia) would be third."
Like Valencia, Kuban also opened up with a Europa League defeat as they were beaten 2-0 by St Gallen and Spaniard Dealbert admits Thursday's match has taken on extra significance because of those results.
He added: "Both teams lost in the first round, as such it will be a crucial game. It will become complicated for whoever loses. We know the great team that we have to face, but we are playing at home and we'll be going out to win the game.
We'll make things difficult for Valencia."
Valencia's turnaround in form has been sparked by striker Jonas, who scored twice in their 3-1 victory over Sevilla and netted the only goal in the wins against Granada and Rayo Vallecano.
However, Los Che will be without the Brazilian in Russia as he has been rested by Djukic, along with fellow forward Helder Postiga, who is struggling with a knock, and midfielder Ever Banega.
That could open the door for young striker Paco Alcacer to stake his claim for a starting berth, with the 20-year-old saying: "What I have to do is take it training session by training session, opportunity by opportunity.
"I'm happy to be included in the list for this competition, which is nice for any player and gives you a lot of desire."