Juan Ignacio Martinez's team are riding high in the table, heading into the weekend fixtures in sixth position, but were on the wrong end of a 1-0 defeat to Segunda B opposition in the first leg of their Copa del Rey fourth-round match.
Navas was one of the players drafted in for the cup clash and is likely to cede his starting spot back to Gustavo Munua.
And his message to his club-mates was to get back to a winning mentality.
"From the beginning we did not have that spark (against Melilla) and we didn't get it right when we wanted to react," he told Marca.
"No-one likes to lose but we have the second leg and it can be done, we just have to give everything when we take the field.
"But you have to change your mindset and think about the next game which is the league. That is what feeds us and that is where we have our targets."
Michel's Sevilla side lie two points behind their visitors and would leapfrog them with victory at Ramon Sanchez Pizjuan.
Los Rojiblancos were successful in their Copa del Rey fixture on Thursday, with late goals from Juan Cala and Alvaro Negredo sealing a 3-1 victory over Espanyol.
Michel bucked the trend by playing a near full-strength side but was not entirely satisfied despite the result.
"The best thing about the game was the result," he said.
"We can play much better."