McKenzie, 14, attended Mason Clark Middle School in East St. Louis. He had college offers from Missouri and Illinois.
McKenzie's mother, Sukeena Gunner, informed KSDK-TV in St. Louis of Elliott's offer to pay for the funeral services. Gunner also said other NFL players have reached out to offer help since her son was hit with a stray bullet at a house party following a prom in Illinois.
A 15-year-old girl was critically injured in the incident.
Elliott, 23, was born in Illinois and attended St. Louis' John Burroughs School during his high school years. Gunner said her son often watched Elliott in order to hone his own football skills.
Elliott is set to make $7.9 million this season, before entering the final year of his rookie contract in 2020. Cowboys chief operating officer Stephen Jones said last week that the team sees re-signing Elliott as a "priority," but there is no timetable on a new deal.