Granada moved away from the foot of the table with back-to-back wins over Celta Vigo and Real Mallorca ahead of the international break and return to La Liga against Zaragoza, who have lost their last two league games.
Zaragoza are currently languishing in 17th place in the overall standings and Lucena knows a win over one of their relegation rivals could be crucial at the end of the season.
"It is essential to win on Sunday. Zaragoza will be a tough opponent," Lucena told the club's official website.
"Getting three wins in a row is very difficult. A result (against Zaragoza) can be decisive at the end of the season.
"We come into this match with much more confidence. The previous victories have been good to us."
Zaragoza striker Helder Postiga is confident hard work will pay off for his side and the goals will soon follow.
The Blanquillos were reduced to nine men against Getafe but still created several good chances before eventually losing out thanks to Diego Castro's second-half penalty.
"With the attitude we had in the match against Getafe we are closer to earning three points," Postiga said in regards to his side's most recent defeat.
"We want to score many more goals as a team. Therefore we continue working and improving in all aspects, both as individuals and as the collective.
"I hope to have the same success I have had in the Portuguese national team."