Betis would provisionally move level with fifth-placed Malaga on 47 points if they beat Granada and victory would also give them the ideal boost ahead of next weekend's derby showdown with bitter rivals Sevilla.
In contrast, Granada are fighting for survival at other end of the table after taking just two points from a possible 18 since claiming back-to-back wins over Real Madrid and Deportivo La Coruna in February.
However, Mel has warned his not to underestimate their fellow Andalusians, pointing out the Granada players will be scrapping for not only the club's top-flight status but their own futures as well.
"Granada are obliged to come out and try to win the game. We know they are fighting against the drop," Mel said on his club's website.
"I've told the players to put themselves in the Granada players' position. They are playing for their contracts."
Betis should not need any reminder of what their opponents can do.
Granada beat Betis 2-1 in Seville earlier this season and by the same scoreline in the corresponding fixture last term as well.
Mel added: "Granada always make things difficult for us. We're expecting an ambitious Granada because they cannot afford to be anything else. They have good players and at home really put you under pressure."
Lucas Alcaraz's Granada are still four points above the drop zone but, with three of the four teams below them gaining ground last weekend, they know they can ill afford another bad result.
Midfielder Iriney Santos, who spent three years at Betis before joining Granada last year, said: "For us the game is a final.
"Our mentality going into the game is to win, win and win.
"We have to respect Betis, but not fear them. We are playing at home and we have to go for them."