In a news release issued on Friday, the Rapids explained the decision as being down to "the confirmed presence of plague-infested fleas affecting prairie dog colonies" in the area surrounding Dick's Sporting Goods Park.
The Plague, known as the bubonic plague, killed an estimated 50 million people in the Middle Ages.
"Our highest priority is the health and safety of our fans, staff, and local community," the team said in its release.
"We will continue to monitor the situation in the lead up to the Rapids home game with Montreal Impact on Saturday at Dick's Sporting Goods Park."
According to the Centers for Disease Control, people typically contract plague if they are bitten by rodent fleas carrying Yersinia Pestis, the bacterium that causes the disease.
Although plague is an extremely serious illness, it is treatable with commonly available antibiotics.
The cancellation of the fireworks show at the stadium in suburban Commerce City, north of Denver, was at the recommendation of the Tri-County Health Department and the City of Commerce City, the Rapids said.
Additionally, at the health department’s recommendation for the safety of those planning to attend the soccer game, parking will be restricted to asphalt lots until further notice.
According to the Rapids, the health department feels that these precautions "will greatly minimise the risk of exposure to patrons, players, and employees and help ensure a safe experience".
Colorado will look to put the plague to one side as they focus on the matter at hand - turning around their woeful recent form.
They are without a win since the end of June and have lost their last two games, against New York City and San Jose.
Montreal, meanwhile, are coming off the back of a convincing 4-0 win against Philadelphia as Lassi Lappalainen and Orji Okwonwko each bagged a brace.