The Yellow Submarine have not won in their past three games, a run of two points from nine dropping them to sixth place in La Liga.
Champions League qualification now looks very unlikely and Jokic knows even a Europa League place could be under threat if they do not turn around their form.
"The only option is to fight in every game, add up the points and get as many as possible," the Slovenia international said.
"Our first goal was to stay up and now we want to fight for a spot in European competition.
"It is the great dream of the manager (Marcelino) and the coaching staff and we will all strive for it.
"There are still many points (to play for) and it will not be easy, but I think we're ready."
Villarreal conceded a late equaliser as they were held 1-1 at home to high-flying Athletic Bilbao last time out and Jokic is wary of the trip to the Mestalla, even if the hosts are not in the best of form either.
Los Che, who went into the weekend in eighth place, have taken just one point from their last three league games, although they have made it through to the quarter-finals of the Europa League.
"It will be a very difficult match, but I think if we play to our strengths we will have our chances," Jokic added.
"Valencia are a team that have changed much from how they played in the first half of the season. They have become a force in the league and will be tough, uncomfortable opponents."