Ross Hassig notes that knives/daggers were used by Mesoamerican soldiers.
Ross Hassig, War and Society in Ancient Mesoamerica (Berkley: University of California Press, 1992), 47
Knives are primarily depicted in mural scenes with implanted hearts, suggesting a ritual use, but they were doubtless used in combat as auxiliary weapons, as was the cast with subsequent Mesoamerican groups. All combatants may have carried them, although representations show them being carried along or by atlatlists, which suggests that these troops followed the spearmen to dispatch captured or wounded soldiers. In any case, they played a secondary role.