The Canary Islands club sit third from bottom in the table and lost 3-0 to Barca in the reverse fixture, but Jemez insisted they must play to win.
He told udlaspalmas.es: “Tomorrow I will not forgive my players for being cowards. We have to go out and fight and be brave to get a positive result against Barcelona.
“I will not do anything strange, you will not see differences with what we have been doing except improvement, we will be faithful to our style of play.
“(Barcelona) are one of the best teams in history. We must see this match as a reward, we are facing a great team and it will be a great opportunity for us to demonstrate our ability because they will demand the best from us.”
For Barca, the match is a chance to open up a 17-point gap over great rivals Real Madrid after Zinedine Zidane’s men lost to Espanyol on Tuesday.
Second-placed Atletico Madrid were seven points adrift ahead of their match against Leganes on Wednesday, and coach Ernesto Valverde is not happy that Atletico have an extra 24 hours off before the clash of the title rivals on Sunday.
He told Marca: “I think we are hurt by the schedule. We are hurt because we play tomorrow at 9pm and Atletico, who are a rival, play today.
“We have to keep winning, there are many days to go. Atletico Madrid are strong and they are having a great campaign. In this week of nine points, at the moment we only have three.”
Valverde could be without striker Paco Alcacer, who was sent home from training on Tuesday with gastroenteritis. Croatian midfielder Ivan Rakitic is set to make his 200th appearance for the club.
It will be the first game for Barca since the death of their former striker Quini at the age of 68.
“It’s a big loss,” said Valverde. “The reaction of the entire football world is significant. He was a born goalscorer from another era but he was always a loving, endearing person. From here, I send my warmest wishes to his whole family.”
Provided by Press Association Sport
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