A listless 0-0 draw against Bordeaux last weekend left Lyon in sixth place in Ligue 1, below St Etienne on goals scored, and Lacombe has demanded more fighting spirit in the 101st derby against Les Verts.
"At the end of a match, a Lyon player should not be able to play another match immediately after like it seems sometimes," he told local newspaper Le Progres.
"Some players don't look tired, they should be empty, completely worn out. Against Bordeaux, it was interesting in terms of intensity but the way we played was insipid."
"We are much too nice," Lacombe added. "It's hot and cold. When we try to balance the positive and the negative, we don't really know. We had seven extraordinary years, now it is harder. If we are not aggressive enough against St Etienne, it is not even worth going," he added.
Lyon coach Claude Puel was more sanguine about his club's position although defeat against St Etienne could scupper their chances of regaining the title.
"The league could stay tight until the end, every point will be important. The month of February will be very important, Puel, whose side face Real Madrid at the end of the month in the Champions League, said.
Champions Olympique Marseille, who are fourth, travel to mid-table Sochaux hoping to produce a better performance than last weekend's dull win over struggling Arles-Avignon.
